Supporting healthy eating in children through the Sensory Interactive Table

Draft report

Supporting healthy eating in children through the Sensory Interactive Table

Sterre van Arum

Supervisors:

Roelof de Vries and Juliet Haarman Critical observer:

Robby van Delden Bachelor Creative Technology

July 17, 2020

Abstract

Eating behaviour has influence on health. Unfortunately, over the years, people started eating less healthy. Because of this, many individuals have a higher risk of getting obesity and heart failure. If we could teach children to eat healthy starting from a young age, they might eat healthy throughout their whole lives.

This goal can be achieved with interactive technology.

This project uses the Sensory Interactive Table. This table is able to display animations and can measure weight. The goal of this report is to create an interactive system that lets children eat healthier with the help of the Sensory Interactive Table.

Based on state of the art, literature research and design sessions with children and adults, I designed three different systems. I focused on the realisation of two of these systems. These systems are named ‘The battlefield in your belly’

and ‘The colourful growing dot’. ‘The battlefield in your belly’ is mainly focused on findings from state of the art and literature. ‘The colourful growing dot’ is more focused on output from the design session.

For the evaluation of the two systems two groups completed in a survey.

One group consisted of adults that participated in the design sessions. The other group was not familiar with this project. Most of the individuals thought

‘The battlefield in your belly’-system would work better than the other system.

However, when asked about the effectiveness of this system, there was not a clear majority of individuals that had the same answer.

To conclude, according to the respondents ‘The battlefield in your belly’

works better than the other system. Based on literature and state-of-the-art I

would say that this system is effective to let children eat healthier. But, to know

this for sure, the effectiveness of this system should be tested with children.

Acknowledgements

First, I would like to thank my supervisors Roelof de Vries and Juliet Haarman and my critical observer Robby van Delden for their feedback and help during this research. I would also like to thank team members of the Sensory Interactive Table (SIT) for giving me access to the control system of the SIT. I want to thank Gijs Keizers as well to help me understand the control system of the SIT.

I would also like to thank everyone that helped me with finding users and proxy-users for the design sessions and evaluation. Furthermore, I would like to thank all the people that participated in the design sessions and the surveys.

Finally, I would also like to thank family and friends that provided feedback on

my bachelor thesis.

Contents

1 Introduction 11

1.1 Background . . . . 11

1.2 Goals . . . . 11

1.3 Research questions . . . . 12

1.4 Outline . . . . 12

2 State of the Art 14 2.1 Related Work . . . . 14

2.1.1 Interactive and Connected Tableware for Children . . . . 14

2.1.2 Sensor Embedded Fork . . . . 15

2.1.3 The Playful Tray . . . . 16

2.1.4 The Cafe Table . . . . 17

2.1.5 Anemone: a social interactive bar . . . . 18

2.1.6 The Garden . . . . 19

2.1.7 Conclusion and Discussion of Related Work . . . . 19

2.2 Literature review: children and food . . . . 20

2.2.1 Literature research outcomes . . . . 20

2.2.2 Methods to let children eat healthier . . . . 21

2.2.3 Methods to make the system child friendly . . . . 21

2.2.4 Conclusion . . . . 22

2.3 Co-design . . . . 23

2.3.1 Importance of co-design . . . . 23

2.3.2 Development of children . . . . 23

2.3.3 Different ways of co-design with children . . . . 24

2.4 Answers to the questions . . . . 25

3 Ideation 27 3.1 Method . . . . 27

3.2 Method of the first session . . . . 27

3.3 First session: Outcomes brainstorm . . . . 27

3.3.1 Attacking germs game . . . . 28

3.3.2 Growing Circle . . . . 29

3.3.3 Growing plant . . . . 30

3.4 Method of the second session . . . . 31

3.5 Outcome second session: Ideas from children . . . . 32

3.6 Method of the third session . . . . 32

3.7 Outcomes of the third session: Ideas from proxy-users . . . . 33

3.8 Method of the final ideas . . . . 35

3.9 Outcome final ideas . . . . 35

3.9.1 The battlefield in your belly . . . . 35

3.9.2 The vegetable garden . . . . 36

3.9.3 The colourful growing circle . . . . 36

3.10 Picking ideas to work on . . . . 37

4 Specification 38

4.1 Ethical implications during a pandemic . . . . 38

4.2 Requirements of a system . . . . 38

4.3 Requirements of the realisation . . . . 38

5 Realisation 40 5.1 Method of the realisation . . . . 40

5.2 Unity . . . . 40

5.3 Unity table . . . . 40

5.3.1 Environment . . . . 43

5.4 Adobe Illustrator and Adobe After Effects with Unity . . . . 44

5.5 Battlefield in your belly process . . . . 47

5.5.1 ‘The battlefield in your belly’-game view realisation . . . 47

5.5.2 Choosing the vegetables . . . . 48

5.5.3 Illustrations and animation . . . . 49

5.5.4 Eating in Unity-game view version . . . . 50

5.5.5 The battlefield in your belly-virtual reality realisation . . 51

5.6 The colourful growing circle-game view realisation . . . . 52

5.6.1 Eating in Unity-game view realisation . . . . 55

5.6.2 The colourful growing dot-virtual reality realisation . . . 55

5.7 Wizard of Oz . . . . 55

6 Evaluation 57 6.1 Method of the evaluation . . . . 57

6.2 Outcome of the survey . . . . 58

6.3 Outcomes of the proxy-users . . . . 58

6.3.1 The battlefield in your belly . . . . 58

6.3.2 The colourful growing circle . . . . 59

6.3.3 Conclusion of the proxy users . . . . 59

6.4 Outcomes of the non-users . . . . 60

6.4.1 The battlefield in your belly . . . . 60

6.4.2 The colourful growing circle . . . . 61

6.4.3 Conclusion of the non-users . . . . 61

6.5 Overall conclusion . . . . 62

7 Discussion 65 7.1 Findings . . . . 65

7.2 Limitations . . . . 67

8 Conclusion and Future Work 69 8.1 Conclusion . . . . 69

8.2 Future work . . . . 69

A Second design session 75

B Third design session 85

C Survey for the non-users 105

List of Figures

1 Interactive and Connected Tableware for Children. . . . 15

2 Sensor Embedded Fork. . . . 16

3 Model that is being used in the playful tray. . . . 17

4 The project Playful Tray (without use on the left, during use on the right). . . . 17

5 The Cafe Table. . . . 18

6 Anemone: a social interactive bar. . . . 18

7 Druin’s onion model. Showing how users can be involved in the designing process . . . . 24

8 Model of the theory of development from Jean Piaget. . . . 25

9 Mind map of the first ideation session. . . . 28

10 The attacking germs game, first stage. . . . 29

11 The attacking germs game, second stage. . . . 29

12 Growing Circle. . . . 30

13 Growing Plant. . . . 30

14 Tilde the Table, illustration for children during the co-design ses- sion. . . . 32

15 One of the children made these colour sections. . . . 33

16 The rainbow from adult 5. . . . 34

17 Image of the two tables in Unity . . . . 41

19 The physical LEDs. . . . 41

18 Flowchart of the process of the Unity file. . . . 42

20 3D model of a plate made in Autodesk Maya. . . . 43

21 3D model of a door made in Autodesk Maya. . . . 43

22 View of the environment for the user. . . . . 44

23 Adobe Illustrator environment. . . . 46

24 Adobe After Effects environment . . . . 46

25 Sprite sheet of a happy jumping tomato. . . . 47

26 Sprite sheet in Unity. . . . 48

27 Animator panel of animations from a tomato. . . . 49

28 The first version of the onion. . . . 50

29 The second version of the onion. . . . . 50

30 When the user eats too fast, a sad tomato appears. . . . 51

31 Confetti idea of adult 4. . . . 52

32 Confetti illustration for the system. . . . 52

33 The rainbow from adult 5. . . . 53

34 Illustration of the rainbow for the system. . . . 53

35 The colour sections from child 1. . . . 53

36 The illustration of the colour sections. . . . 53

37 The growing dot from adult 8. . . . . 54

38 The illustration of the growing dot for the system. . . . 54

39 The fireworks from adult 9. . . . 54

40 The illustration of the fireworks for the system. . . . 54

41 Final answer of the proxy-users on healthy eating ‘The battlefield in your belly’. The x-axis shows how many people chose an answer. 60 42 Answers of the non-users on comparing the two systems. The

x-axis shows how many people chose an answer. . . . 62

43 Answers of the proxy-users on healthy eating ‘The battlefield in your belly’. The x-axis shows a rating scale. 1 meant the user disagrees with the statement, 5 meant the user agrees with the statement. . . . 63

44 Answers of the non-users on healthy eating about ‘The battlefield in your belly’. The x-axis shows a rating scale. 1 meant the user disagrees with the statement, 5 meant the user agrees with the statement. . . . 63

45 Answers of the both of the users to the same question displayed in one bar graph on healthy eating about ‘The battlefield in your belly’. . . . 64

46 First idea of child 1 . . . . 75

47 Second idea of child 1 . . . . 76

48 Third idea of child 1 . . . . 77

49 First idea of child 2 . . . . 77

50 Second idea of child 2 . . . . 78

51 Third idea of child 2 . . . . 78

52 First idea of child 3 . . . . 79

53 Second idea of child 3 . . . . 80

54 Third idea of child 3 . . . . 81

55 Fourth idea of child 3 . . . . 82

56 Fifth idea of child 3 . . . . 83

57 Sixth idea of child 3 . . . . 84

58 First idea of adult 1 . . . . 85

59 Second idea of adult 1 . . . . 86

60 Third idea of adult 1 . . . . 87

61 First idea of adult 2 . . . . 88

62 Second idea of adult 2 . . . . 89

63 Third idea of adult 2 . . . . 90

64 First idea of adult 3 . . . . 91

65 Second idea of adult 3 . . . . 92

66 Third idea of adult 3 . . . . 93

67 Ideas of adult 4 . . . . 93

68 First idea of adult 5 . . . . 94

69 Second idea of adult 5 . . . . 95

70 Third idea of adult 5 . . . . 96

71 First idea of adult 7 . . . . 97

72 Second idea of adult 7 . . . . 97

73 Third idea of adult 7 . . . . 98

74 First idea of adult 8 . . . . 99

75 Second idea of adult 8 . . . 100

76 Third idea of adult 8 . . . 101

77 First idea of adult 9 . . . 102

78 Second idea of adult 9 . . . 103

79 Third idea of adult 9 . . . 104

1 Introduction

1.1 Background

Eating behaviour has influence on health [1]. When an individual eats healthy they have a low risk of getting several diseases (such as obesity and heart failure) [1]. Inherently, a healthy individual preserves a balanced diet [2]. A balanced diet involves taking the right portions of specific food groups throughout the whole day, such as fruits and vegetables, carbohydrate foods, meat, fish, and alternatives, milk and dairy products, and fatty and sugary foods [3]. Although information about preserving a healthy diet is available, upholding a healthy diet tends to be a problem.

Over the years, adults started eating less healthy [4]. In addition, children started eating unhealthy as well [5]. Neglecting a healthy eating behaviour can cause complications. For instance, an unhealthy eating behaviour can lead to obesity [5]. Child-obesity especially is an increasing problem. The percentage of child-obesity in the United States has doubled in 30 years [6]. Three factors influence this problem. First of all, the exposure of fast food on television has influence on the eating behaviour of children [7]. The second factor involves the influence of the eating behaviour of peers [6]. The third factor is about the eating values one takes from their environment [8]. For more and more people, these eating values do not fit with a well-balanced diet. Learning an appropriate diet might help with maintaining a healthy lifestyle. However, children can find it hard to understand that eating healthy is beneficial.

Learning a well-balanced diet at a young age can influence the eating be- haviour for the whole lifespan of a person [9]. Studies confirmed interactive tech- nology as a successful approach to stimulate children to eat healthier [10, 11].

One way to teach children to eat healthier is through using interactive technol- ogy. With interactive technology, information about food can be provided to the children in a new engaging way.

1.2 Goals

This report focuses on the design of an interactive system that lets children eat healthier. For the sake of evaluation, this report concentrates on eating during dinner time. In most circumstances, dinner time happens at tables.

Thus, a dining table is the perfect place to stimulate children to eat healthier.

Researchers at the University of Twente made the Sensory Interactive Table [12]. The table could stimulate healthy eating among children. The Sensory Interactive table has 199 load-cells, which can measure weight. The load-cells can also detect weight shifts on the table. Additionally, the Sensory Interactive Table has 8358 LEDs. With these LEDs the table can display animations. The combination of the load-cells as an input and the animations as an output can create a meaningful interaction. The Sensory Interactive Table does not have a suitable interaction for children yet.

To create a suitable interaction for children, this requires relevant informa-

tion. Firstly, I need information about the eating habits of children. Secondly, I need to find methods that engage children to eat healthier. An approach to consider is to let children like eating healthy. As a consequence, they might associate certain foods with a positive feeling. Furthermore, I need to find state of the art projects related to eating healthier among children. With the state of the art, I might gain new insights on how to approach this topic. And fi- nally, since the user group is a specific group, I need to find more information about the design principles for this group. With this information, the interac- tion system for the table can be designed. The main goal is to guarantee that the interaction engages children to start eating healthier.

1.3 Research questions

To reach the goal of this report, I need to formulate research questions. This section shows the research questions. The following question is the main research question of this report:

• ‘How can interactive dining be designed that stimulates healthy eating in children?’

To address this broad research question, sub questions are formulated as well. Firstly, I want to investigate research about eating habits and similar interventions. These sub questions cover the human food interaction and eating aspects:

• ‘What are the general problems regarding children which are eating unhealthily?’

• ‘What are technical interventions that have proven to stimulate children to eat healthy?’

And finally, when I design for children, I need to take different aspects into account. The following sub question covers the design method for children:

• ‘What are the standard methods used to design for children?’

1.4 Outline

This report consists of several chapters. The following chapters provide infor- mation that is necessary for this bachelor thesis. This subsection provides an outline for the coming chapters.

Chapter 2 first shows projects that are in some way related to this bach- elor thesis. Chapter 2 also introduces information about the user group and methods that are most used with the user group. Additionally, chapter 2 offers information about factors that influence eating behaviour of children.

The following chapter, chapter 3, provides an outline of the used methods

for the ideation-, realisation- and evaluation-phase. Chapter 4 discusses the

outcomes of the ideation sessions and the final ideas for the interaction systems.

Chapter 5 depicts specifications for the system. Chapter 6 provides details about the realisation process. The next chapter, chapter 7, discusses the details of the evaluation procedure.

Chapter 8 introduces the conclusion and discussion. This chapter explains

the push backs and gives answers to the research questions. Finally, chapter 9

concludes with possible future work that is related to this project.

2 State of the Art

2.1 Related Work

This section gives an overview of existing projects and products that concern the field of interactive dining. Through literature, searching on the web and notes from teachers or students, I found these projects.

2.1.1 Interactive and Connected Tableware for Children

This project: Interactive and Connected Tableware for Promoting Children’s Vegetable-Eating and Family Interaction, focuses on creating a system that aims to encourage children to eat more vegetables. Furthermore, this system focuses on educating the same children about the benefits of healthy eating [13]. An important feature of this table is to guarantee child-parent interaction during eating. The system consists of a food tray, a spoon, and a smartphone cradle.

The product can be seen in Figure 1. Additionally, the researchers created an application for the system. This application has a few mini games that teach and motivate children to eat healthier. Before the real game begins, a child takes two pictures of their face, one with a normal expression, and one where the child smiles. This is for later on. When the child performs well during the game, a small icon above the smartphone cradle shows the picture of the smiling child. After the pictures are taken, the real game can begin. The child selects the amount of vegetables they want to eat. The child can increase the amount of vegetables later on. If the child increases the amount of vegetables, they go to a higher level. The child is then able to play the game.

For the game, they can choose between a game with a tomato, or a game with a broccoli. Depending on what vegetable the child chooses to eat, the child plays a different game. At the beginning of both the games, the child learns about the health benefits of the vegetables. After this, the child plays the chosen game. The broccoli game shows the child their bowels. The bowels seem ‘ill’, but when the child eats a piece of broccoli, the bowels look healthier.

If the child eats all their pieces of broccoli, the bowels look happy and show a

‘satisfied’ excrement. The other vegetable game is a bit different.

The tomato game shows again the bowels. The tomato wards off bacteria in the bowels. If the child eats their portion of tomatoes, the bowels look healthy.

After each game, the child gets a quiz about the benefits of the vegetables.

When finishing this quiz, they get a vegetable medal.

The system was tested with two families with children who hated eating vegetables. After the pilot study, the behaviours of the children changed signif- icantly. The children showed to like the food and to have learned traits of the vegetables. During the test, the children interacted with their mother and the game, while eating the vegetables.

The system seems to have an immense value regarding child-food interaction

with a computer. However, as the article already states, not many children

tested the system, only two, and no research is done about the long-term use

of this system. Moreover, the system had a limited variety of games. Children are likely to get bored after a few sessions playing the same game. Thus, more games should be considered in the future.

Figure 1: Interactive and Connected Tableware for Children [13].

2.1.2 Sensor Embedded Fork

This project is for children that are picky eaters. The system consists of a fork, a mobile application, and a game. The project can be seen in Figure 2. The system tries to encourage the child to eat healthier. Additionally, the system tries to inform the child about healthier food. The game is a storybook and a persuasive game. The game involves a story about a hungry panda. This game is made and used in an Asian country, as a consequence the designers chose the panda as ‘companion’. The eating performance of the child has influence on the eating of the panda. The game detects when the child performs eating actions.

The system distinguishes between four phases through the Sensor Embedded Fork, namely At Rest, Holding, Poking and Biting. The basic design of the game is the panda that imitates the child’s eating behaviour. The game tries to let the child feel sympathy for the panda by giving the panda ‘food’

through the child’s own eating actions.

This game consists of two parts. The first part involves a storybook with

information about eating. This part does not have a voice over, thus making

sure the parent will read the story out loud to the child. The second part is

a ‘point’ system. The child collects the points during the eating process. The

panda holds and eats the bamboo, the same way the child does this with the

Sensor Embedded Fork. The story part shows a panda that greets the child and

hints to the child that dinner time is almost starting by telling the child they

feel a bit perky. After this the panda will explain to the child that the panda

wants to eat different coloured bamboo, hinting at the different types of food

the child needs to consume. The child gets information about the certain food

types. After this, part two comes into action. The child sees the panda that

wants to eat the bamboo. Then the child starts eating. After this, the game is

finished. To check the reliability of the system, the researchers conducted tests.

Parent-child participants did some of these tests. The results of these tests show that a positive effect is found for changing the children’s food behaviour.

This game is mainly focused on two problems regarding eating behaviour. The fact that some children are picky eaters and the fact that children are easily distracted. The systems have all kinds of small features to guarantee the child keeps eating. For example, the game uses music to stimulate the eating be- haviour of the child. Another example: when the child does not touch the fork for a while, and suddenly touches it again, the panda smiles [10].

Figure 2: Sensor Embedded Fork [10].

2.1.3 The Playful Tray

The Playful Tray is a tray that lets children eat better through a play-based therapy [11].

The tray has an interactive surface with weight sensors, which can check if the child is eating in real-time. The tray focuses on a racing game, in which the child needs to eat to make sure a character runs. The child gets points for eating, which makes the character run. If a child eats too fast, the game sends a notification telling the child to slow down. If the child does not comply, the child does not get points. The tray can be seen in Figure 4. The study conducted a pilot test with four children.

The conclusion of this study suggests that the Playful Tray may cause a

better meal experience for the child and the parent. The Playful Tray focuses

mainly on the play experience of the child and the benefits of using a playification

approach. The Playful Tray uses the model of human occupation (MOHO). An

occupation is caused because of three subsystems of a human being. These

subsystems are:Volition, Performance, and Habituation [14]. This can be

seen in Figure 3. To guarantee that children perform a task often, the children

need motivation to perform the task, which, if performed enough over time,

eventually becomes a habit. With this model in mind, the Playful Tray worked

on their product. Through this model they defined four different aspects they

should focus on while designing the Playful Tray. These aspects are namely:

Figure 3: Model that is being used in the playful tray [11].

Attention, Enjoyment, Engagement and Control. This design connects and integrates the fun part (coming from the digital game activity) with the activity of eating [11].

The behaviour of the children does seem significantly change when using the tray. However, only four children participated in this test and no long-term study has been done. Thus, the researchers do not know if the eating behaviour of the child eventually changes for the better. The Playful Tray is a promising asset regarding playification of consumption for children.

Figure 4: The project Playful Tray (without use on the left, during use on the right) [11].

2.1.4 The Cafe Table

The Cafe Table is a project that engages users to talk to each other in a museum [15]. The table senses when there is a silence and tries to give subjects which the users can talk about. These subjects are related to the museum that the users are in. The table can be seen in Figure 5.

The table has a system that listens to the users to determine when a con-

versation is happening or stopping. The table has a projection of a pool with

some fish. When the system senses the conversation is slipping away, the table

shows in front of each user a card with an image of the museum. When the table senses a conversation is starting again, the table lets the cards disappear, to ensure the users are not distracted by them.

Figure 5: The Cafe Table [15].

2.1.5 Anemone: a social interactive bar

Anemone: a social interactive bar, is a project made at the University of Twente [16]. This project is an interactive bar that shows projections on the bar of fish- like creatures. The bar can be seen in Figure 6. This bar was meant as an ice breaker for contact with other people in the bar. The designers of this project did this by using interesting visuals and interactions between users.

Figure 6: Anemone: a social interactive bar [16].

2.1.6 The Garden

This project tries to let children eat healthier with the help of a garden. The researchers let children plant and work in a garden twice a week during a time period of 12 weeks. During the 12 weeks, the children received information about the benefits of the vegetables and fruits they were growing. The project showed that when children are involved during the growing of their vegetables, children are likely to eat more vegetables and fruits. This outcome might then result in a healthier lifestyle [17].

2.1.7 Conclusion and Discussion of Related Work

In the projects that involved children, it is clear that playification can be success- ful when changing the eating behaviour [10, 11, 13]. These three projects have an educational component as well, which seems to help getting the children to understand about the benefits of eating healthy [10]. The children’s eating be- haviour changed significantly in all these projects. It is however unknown if this is the case for many children, since the projects were often only tested with a very limited number of children. The projects show that the children want to change their behaviour when they learn about the benefits of healthy eating.

Especially the Interactive Tableware showed that the children gained knowledge about the benefits of eating vegetables [13].

Something to take into account is that no longitudinal studies were done.Another aspect to take into account is that parents need to be involved in the game [13].

The game should be abundant in mini games or have some variety. It is very

likely the children will get bored after playing the same game repeatedly [13].

2.2 Literature review: children and food

To understand more about how to persuade children to eat healthier, this section looks into literature that provides information about child-food interaction. This section gives an overview on the obstacles children have regarding eating healthy and the methods that are used to persuade children to eat healthy. Information about how to design for children is provided as well

. Firstly, the next section looks into the different factors that influence eating behaviour.

2.2.1 Literature research outcomes

The eating behaviour of children is determined by different factors. Literature provided information about the different factors, which led to these causes. The amount of different causes was small, I believe that this could mean the following of the three cases. This could indicate there are only a limited amount of causes for the eating behaviour. This could also mean that this topic is not researched enough yet. Or this could mean that it is hard to prove that these factors really cause a bad eating behaviour. According to Krølner [18] there is not an abundance of different factors that influence the eating behaviour of children.

An example for one factor, the older you get, the healthier you eat. Another example is that girls eat healthier than boys. The following are aspects related to eating behaviours of children according to Krølner:

• The gender of the child

• The age of the child

• The social and economic position of the environment of the child

• The parental intake of food

• Accessibility/Availability of food

Other studies showed that parental eating behaviour has a significant influ- ence on the eating behaviour of the child [19], which is in line with one of the aspects that Krølner talks about. Another study states that eating behaviour of children is influenced by the eating behaviour of other peers [6]. This is some- thing to take into account, since if the child’s behaviour needs to be changed, the behaviour of peers/parents needs to be changed as well.

To summarize, the eating behaviour of children is influenced by the gender, age, social and economic position, peer influence and through the accessibil- ity/availability of food. It is easy to focus on peer influence, since this is a factor that designers can take into account when designing an interactive sys- tem. For instance, they could make a system that tracks the eating behaviour of peers. The peers might for instance have to slow down while eating. This is to assure the child eats healthy too. Since the eating factors are now known,

1

This literature review was made by myself for the final assignment of the course Academic

Writing for module 11 of the study Creative Technology.

it is easier to take these factors into consideration when making an interactive system for children. To make sure the interactive system is more engaging, persuasive methods for the children should be applied to the system as well.

2.2.2 Methods to let children eat healthier

There are several methods to persuade children to eat healthier. One main successful method to persuade children is to use gamification of food intake [10, 19–22]. Other studies show that when an educational component is used regarding fruit and vegetable intake, the children are likely to eat the fruit and vegetables [23]. The educational method seems very effective in multiple studies that the paper investigated [23]. Additionally, involving children to help with preparing the meals is another successful method [24]. Another way to persuade children is to use rewards. These can be either tangible (for instance, stickers) or non-tangible (for instance, praise) [25]. Many different approaches can be used to persuade children to eat healthier.

To conclude, gamification is successful when changing the eating behaviour of children. It will also be more fun for the children to use a game. Since there are many sources that are using this method and seem to have succeeded [10]

in their goal, this method is used. An educational component and a reward component seem to be successful as well and these two components are used as well [10, 23].

Since the insights about the causes and methods that influence children’s eating behaviour are gathered, the next step is to determine how to make the system child friendly. To ensure that the children are getting a fitting system specifically targeted at this user group, design principles should be used that regard this target group.

2.2.3 Methods to make the system child friendly

In this section several methods are described to make the system suitable for the user group. One method to do this is the use of Participatory Design or co-design. This is a methodology that includes the end users in the process of developing the system or product [26]. [27] suggests almost the same procedure, namely, to let children make games for other children. Yet, [28] stated that there are many factors that need to be taken into account when designing for children. Several methods are be explained in the following paragraphs.

According to Piaget social interaction seems to be a key role in develop-

ment [29]. This is because an older generation (for instance parents) can pass

on knowledge to a younger generation (for instance children) [30]. Therefore,

educational technologies should have a social component to make sure that the

children can interact with other people. According to the study, children should

be able to have influence on the story [31]. They should not only absorb facts

but participate in the story. Another way to motivate children about the edu-

cation the children receive, is to make the activities relevant to the lives of the

children [32].

Another approach that is able to successfully use a learning component is storytelling [33] [34]. This can be used with or without a game component [33]

[34]. Another concept that is used is scaffolding [30]. Scaffolding means that help is offered to the children when they are trying to complete a task. Afterwards they can complete the task on their own. This means, however, that when the system does this, social interaction of others is not needed [28]. This might lead to the isolation of the child, which can lead to negative consequences. Therefore, the interaction system should be social. The children need help from other people, or should still interact with other people while using this system [28].

Something else that designers should keep in mind is that children need quick feedback [35]. If the children do not get this feedback, they may get bored and move to another activity. Another aspect is whether the children can read or not, and thus making use of text might have to be avoided [28].

As can be seen, many aspects need to be taken into account, it is however not clear if there is a method that seems to work as the best method. The co-design method seems to be done quite often and seems to work sufficiently according to different studies. It is important to involve your user group in the design process to make sure that the user group likes the product. This is an aspect that is useful for this project. The storytelling aspect could be helpful as well, especially for designing a game. With a storytelling game, children are entertained and could get informed as well. The scaffolding concept does not seem very helpful, since this would mean that social help from others is not necessary.

2.2.4 Conclusion

From the literature reviewed in this chapter, I can conclude that the eating

behaviour of children is influenced by the gender, age, social and economic

position, peer influence and through the accessibility/availability of food. The

ways to persuade children to let them eat healthier are gamification, usage

of an educational component and usage of a reward component. The design

principles for children involve many different aspects. It is not clear for the

design principles if one method is more efficient than the others, because of this

a preference for the design principles is not stated. However, for the project use

of co-design, storytelling, and a form of gamification (playification) [36] is used,

since these are considered very suitable for this project.

2.3 Co-design

The method that is considered suitable for this project is co-design. Because of this, I searched for more information about this method. I attained this in- formation through literature research. The following sections show information about this method.

2.3.1 Importance of co-design

Co-design is a way to design for clients and/or users. This design method is a user-centered way of creating a product [37]. Children can be involved in the designing process but can also be involved as users. This design method has benefits as well. These benefits can be categorised into three different sections, namely:

• Benefits for the service design project

• Benefits for the service’s customer or user

• Benefits for the organization(s) that are involved

Benefits for the service design project are improvement of the ideation phase, understanding of the user’s needs, developing better definitions for the services, and improving the concept. Companies and/or organizations also expected to have a better connection with the user/customer that they were working with.

Not only the companies and/or organizations benefit from this process, users benefit too. A benefit for the service’s customer or user is that users are able to create a service that fits their needs. This can lead to a higher satisfaction for the users. Co-design overall has benefits for all parties involved [38].

The ‘onion’ model of Druin is often used in a user-centered design process [37]. Figure 7 shows different ways of how a user is involved in the designing process. Co-design can be very helpful to cover every aspect of this model.

The (possible) users are asked to help with designing. Then afterwards, these users can be asked to give information or more feedback for the design. When designers make a design, designers can also ask these users to participate in the test phase. Since contact was already established, it is relatively easy to ask the users to test the product as well.

2.3.2 Development of children

When designing with and for children there are many factors one should con- sider. These can be individual factors as well as environmental factors. When co-designing with children, a factor which should be taken into account is the age of the child [37]. Children all develop differently. This has to do with the cul- tural and personal factors the child is exposed to. When children are aging, the children develop their abilities over time and not from one day to another [37].

According to the model of Jean Piaget, the theory of development, see figure 8,

children gain the intuitive thought around the age of 4 till 7 years old. Thus,

Figure 7: Druin’s onion model. Showing how users can be involved in the designing process [37].

for this project I decided to work with children starting from 6 to 12 years.

The older the children are, the more developed they are likely to be [37]. It is however necessary to consider how to persuade the children depending on their age. Children which are for instance 12 years old, are better at understanding hypothetical situations than children which are 6 years old [29]. Some children have difficulty understanding what is asked from them, I keep this in mind. The language that is used during the co-design sessions are simple.

2.3.3 Different ways of co-design with children

There are numerous ways to use co-design with children. In this section a few examples are shown.

One way to use co-design is in groups. This technique can be done quite often compared to other techniques. One way of doing this is Layered Elaboration.

This technique works with groups of children. One group works on the ideas another group made. In this case, all the children work in an iterative process [39].

Fictional Inquiry is another way of using co-design. Fictional Inquiry is a method where a story is used to motivate the children to generate ideas.

For instance, with Mission to Mars, children are contacted by ‘Martians’. The

Martians do not understand anything that happens on our planet. Because of

this, children are likely to explain more towards the Martians about their ideas

Figure 8: Model of the theory of development from Jean Piaget [37].

than towards adults [40].

Storyboarding is another effective way to get children to come up with ideas.

Storyboarding is a way to show a sequence of actions. Storyboarding can be made more suitable for children. This method is called Comic boarding [40].

Through Comic boarding, a child tells an adult what should happen in the storyboard. The adult sketches these ideas in the storyboard. Another method that can be used is Magic Comic boarding, which is a slight variation of Comic boarding. With Magic Comic boarding, the child sees the storyboard in front of them and explains what has to happen in the storyboard. This storyboard can be displayed on a computer. In another room, a skilled artist can hear what the child says and draws the explanation of the child [40].

Another method used in co-design is Distributed Co-design. This is espe- cially made for parties that are not able to meet in person, normally because of location issues. Through the Internet it is possible to ‘meet’, discuss and generate ideas. Co-design can be done at the homes of the users and the homes of the researchers [40]. When using Distributed Codesign, or DisCo for short, it is also possible to integrate the methods mentioned before. DisCo is a special tool that was especially developed for this method [40].

2.4 Answers to the questions

Since I found sufficient information, several research questions can be answered.

This section shows answers to the several research questions.

• ‘What are the general problems regarding children which are eating unhealthy?’

The general problems regarding children that are eating unhealthily are the

gender, age, financial status, social status and peer influence.

• ‘What are technical interventions that have proven to stimulate children eat to healthy?’

The technical interventions that have proven to let children eat healthy are the Interactive and Connected Tableware for Children, the Sensor Embedded Fork, and the Playful Tray. All the three interventions have a play factor and an educational factor. This is considered when designing the interactive system.

• ‘What are the standard methods used to design for children?’

There are different methods different designers use when they design for

children. The most common used method is co-design. Because of this, I use

this method as well for this report. The system uses some other methods as

well for this project, such as story-telling and playification.

3 Ideation

This chapter shows the outcomes of the ideation phase. This chapter shows the method and all the results of the three sessions.

3.1 Method

During the ideation phase, different (co-design) sessions took place. The follow- ing sections explain each session and how this results in the final idea. For the ideation phase I came up with three different sessions. The first session was a brainstorm session with me. The second session and third session involved users and proxy-users. The second session, involved users, children, which designed ideas for the table. The third session involved proxy-users, adults, which de- signed ideas for the table. I asked the adults to participate, since it was difficult to contact the children. The next section shows the outline of the first session.

3.2 Method of the first session

In this session I looked for requirements in literature and state of the art. I decided to do this since I have a different view on the system then the (proxy-) users have. This is because of the knowledge I gained through literature and state of the art. After analysing the state of the art and the literature, I listed a few requirements.

These requirements are:

• To have a game-like feature in the system

• To provide information about the benefits of healthy eating

• To let parents take an active role during the eating activity

• To let the child memorise the information about the benefits by repetition of the information

• To make sure the food is consumed in a proper time length

• To involve other peers during eating

Some projects used a companion throughout the interaction. It is not nec- essary to use this buddy, but it is something to keep in mind. After I listed the requirements, the ideation phase could start. I used a mind map to come up with ideas. Based on the mind map, I sketched more and different ideas. The next section describes the outcome of the first session.

3.3 First session: Outcomes brainstorm

Firstly, I used a mind map to generate ideas. Figure 9 shows the mind map.

Based on the mind map, I made sketches. After this, a few ideas came to form.

The following three ideas were the most suited and came to mind:

Figure 9: Mind map of the first ideation session.

• Attacking germs game

• Growing circle

• Growing plant game

The following sections explain more about these ideas.

3.3.1 Attacking germs game

This game focuses on teaching the children about the health benefits of the vegetable that they are eating. The goal of this game is to make sure germs do not attack the plate of the child, and thus making the child sick. The idea is that the children can choose which vegetable they are playing the game with.

The vegetables the children choose are preferred to be the vegetables that they are eating. There are a few stages in this game.

In the first stage, the vegetables surround the plate of the child. This plate stands as the home base of the child. When the child is eating, the vegetables tell about their specified benefits. While the child is eating, the attack bar of the vegetables increases gradually. See Figure 10 for concept art for the first stage.

In the second stage, the germs start to attack. The germs emerge very

slowly. When the child starts eating, the vegetables spit seeds, as if it were

Figure 10: The attacking germs game, first stage.

ammunition. If the child eats too fast, the vegetables miss. If the child eats slowly, the vegetables hit the germs. See Figure 11.

Figure 11: The attacking germs game, second stage.

In the last stage, when all the germs have been defeated, the vegetables thank the child for eating. They ask the child about the benefits of themselves and hold a short quiz about these benefits.

3.3.2 Growing Circle

The next system is relatively simple and does not focus on informing children

about benefits of a balanced diet. A small circle appears in the middle of the

table. The plate the child uses to eat, sends small circles to the circle in the

middle. Because of this, the circle grows. If the child has finished their dinner,

the circle covers the whole table. See Figure 12 for concept art.

Figure 12: Growing Circle.

Figure 13: Growing Plant.

3.3.3 Growing plant

The final system focuses primarily on the informative part and the speed the

food is consumed in. The system shows the plant of the vegetable the child

is preferably eating. Speakers are connected to the table as well. When the

child eats, the plant grows. If the child eats too fast, the plant grows too fast,

becomes too thin, and falls. A voice over explains about the benefits of the

specific vegetable that is displayed on the table. When the child finished their

plate, the plant grows its first vegetable. See Figure 13 for concept art. After

this, the second session could start.

3.4 Method of the second session

Designers often forget, or do not always understand, what a user wants. With co-design, the users’ needs are more understandable, and the final product is more suitable. Because of this, I decided to integrate co-design sessions. Unfor- tunately, an event occurred that I did not prepare for.

Because of COVID-19, children participated in a different way in the co- design process. The schools closed during the ideation phase. It would be time consuming to make individual video calls with children. Not to mention, possible difficulties that may occur (for example: bad internet connection or no available microphone). Since the parents are home as well, they probably need the devices for work related activities. The parents got instructions instead to help the children with the co-design part.

I designed the instructions based on the co-design method Fictional Inquiry.

I used a small story to motivate the children to make ideas. I wanted to let the children feel comfortable with making ideas. The character in the story focuses on asking the children if they know a solution. The children might tell more ideas to the table then to an adult. The character Tilde the Table is an interactive table that can sense when and where the children are eating on Tilde. Tilde the Table asks the children to help her generate ideas for certain actions. The table gives some information to the children about what she can do. For the design session to take place, the parents got instructions.

The parents got a story about Tilde. The table gave three scenarios to the children. In the first scenario, the table explained that she wanted to welcome the children. In the second scenario, Tilde asked the children to help to show children that she knows they are eating healthy. In the third scenario, Tilde asked to illustrate how she should show that the plate was empty.

The children could illustrate this with two different methods. The first method is for parents who do not have enough time to supervise their children.

They would tell the story and let the children colour in colouring pictures. See Figure 14 for one of the colouring pictures. If the parents had more time to supervise their children, the children could do some art crafts.

When the children finished, parents took pictures of their work and sent it

towards me. The parents send consent forms towards me as well. This form

indicated if the parents wanted to let their children participate in the future.

Figure 14: Tilde the Table, illustration for children during the co-design session.

3.5 Outcome second session: Ideas from children

This section gives a small overview of the ideas of the children. I got three responses from children. Appendix A shows the ideas of the users. I used some of the ideas as inspiration for the final system. This section discusses elements of the ideas of the children.

Child 1 and child 2 had very similar ideas. For the first scenario, the children divide the surface of the table in colour sections. Figure 15 shows the colour sections Child 1 and Child 2 made. In the third scenario, the table can talk and gives compliments. Child 3 made a few additional features. One of these features shows when a child is taking their first bite, the table will show the number ‘1’ around the plate.

3.6 Method of the third session

This section explains the method of the third design session. Something that I had not foreseen was the response rate of the co-design sessions. Many parents were busy during this time. They were a teacher for their children and did their regular job at home. Many parents suddenly had two jobs in a very short amount of time. This probably led to a smaller response rate than anticipated.

As a consequence, I asked another user group to participate in the co-design sessions. This group is significantly different from the initial user group.

Children ranging from 6 to 12 years old were not easily attainable. The

logical next group were children between 13 and 17 years old. However, the

plan was not to ask this group. The same issues could occur. The children in

this age group might suffer from stress due to the COVID-19 crisis. Ethical

Figure 15: One of the children made these colour sections.

issues also played a role. Thus, I asked individuals starting from the age 18 till the age of 23 to participate. I adjusted the instructions to a more suitable use of language. I asked this group to pretend they were children. This group was allowed to draw, or just use text for their ideas.

3.7 Outcomes of the third session: Ideas from proxy-users

This section gives a small overview of the ideas of the adults. I got nine responses from adults. Appendix B shows ideas of the proxy-users.

Three adults depicted a scenery view. Adult 1 displayed a garden on the table. As you keep eating, the garden grows. Flowers grow around the plate.

Animals appear as well. Adult 9 had a similar idea. When you eat, a plant grows until it becomes a tree. If you finish a meal the child will get a ‘snack’

from the tree as a reward. Adult 3 depicts a mountain climber that wants to climb a mountain. When you keep eating, the climber climbs to the top of the mountain. The goal is to reach the top and admire a beautiful scenery.

Adult 8 drew a growing circle around the plate. When you eat, the cir- cle grows. Adult 3, Adult 4, Adult 7, and Adult 9 invented a point system.

The children can pick healthy or unhealthy food. When the children choose

unhealthy food, they get minus points. If the children pick healthy food, they

get plus points. Adult 4, Adult 5, Adult 7, and Adult 9 came up with a few

additional features. Adult 4 and Adult 9 depict a rainbow animation. Adult 4

and Adult 7 want to use confetti, as a reward for finishing the meal. Adult 9

displayed fireworks as a reward for finishing the meal. Adult 5 depicts a ‘soft’

rainbow. The colours are in pastel. Figure 16 shows the rainbow.

Adult 8 and Adult 9 also came up with a competitive eating game. In this game, multiple users had to eat as fast as possible to grow a circle. If t

Figure 16: The rainbow from adult 5.

3.8 Method of the final ideas

After these sessions, I investigated the results. I looked at the ideas of the second and third session. Afterwards I gathered the drawings, I would underline what stood out to me, or what I would like to use for the final idea. After this happened, I looked at ideas from the first session. I combined the three sessions into a few ideas. Then the requirements showed if the systems were compatible enough. I made a choice on which system I would work on. I did this based on how many requirements the system meets and how many aspects of the second and third session the system integrated.

3.9 Outcome final ideas

The following sections show the final ideas. These ideas are combinations of the self-ideating phase and the ideation of the (proxy-)users. The ideas are:

• The colourful growing circle

• The vegetable garden

• The battlefield in your belly

The following sections explain each idea.

3.9.1 The battlefield in your belly

First of all, at the beginning of this system, the table shows different vegeta- bles. Speakers are attached to the table. These speakers give information or instructions. The speakers ask the child to pick the vegetable they are eating today. After the child has done this, the game can begin. The game consists of three phases. The first phase is an information phase. During this phase, the chosen vegetable gives information about their benefits. In the first phase the chosen vegetable appears on the surface of the table. The background looks like a fleshy environment, indicating that the vegetables are inside a body.

After this the second phase starts. In this phase, a germ appears from the one side of the corner. The germ slowly proceeds towards the plate. The vegetable then indicates that the child has to eat, but not too fast, since the vegetable becomes sad if the child does this. When a child eats, the vegetable shoots seeds towards the germ. The germ dies when the plate is finished. Then the vegetable celebrates the victory of defeating the germ.

Then the third phase begins. In this phase the vegetable asks the child to

answer a question. The vegetable asks a question about information that the

vegetable provided in the first phase. This is a yes or no question. The child can

use the load cells as buttons. Two buttons appear on the table, one indicates

as yes, the other indicates as no. If the child gives correct answers, confetti

appears on the table. After this, the vegetable thanks the child and the system

stops. This version is for when one person eats.

More players can participate as well. The germ spawns from the side. The quiz round is a bit different as well. Then, the vegetable asks if everyone around the table can discuss and give an answer as a team.

This system has most of the goals of an ideal system. The system is a game, it provides information, helps the child memorising the facts, the food is consumed in a proper time length and peers can be involved as well. The parents can take an active role during the eating. The child might ask for help with memorising the facts. The parents can help the child and can praise them.

It is however not sure if the system involves the parents as well if they are not eating. This needs to be tested.

This system does not have many features from the co-design sessions. The one main thing that is used from the co-design sessions is the confetti.

3.9.2 The vegetable garden

The goal of this system is to grow a beautiful vegetable garden. The table has speakers to provide information. When the child eats, the garden grows. If the child eats too fast the plants die. While the child eats, the speakers provide information about the vegetables that grow. After the whole garden is filled with vegetables, a quiz starts. The table zooms in on a few vegetable plants.

The table asks questions about these plants. These are ‘yes’ or ‘no’ questions.

The child can answer by using two load cells as buttons. Two buttons appear on the table, one indicates as yes, the other indicates as no. The whole garden grows vegetables if the child has some correct answers. If another child wants to eat as well, the system stays the same. The individuals have to answer the questions as a team.

This system covers most of the goals for an ideal system. This system has game like features, provides information, helps the child with memorising the information, the food is consumed in a timely manner and peers are involved in the eating process as well. This system might involve the parents, but this is not guaranteed. Tests need to be done to determine this.

This system does have features from the co-design sessions. These features are mainly from the proxy-users.

3.9.3 The colourful growing circle

This section explains the final idea. The children had a preference for the use of colour as did some of the adults. The table has speakers, to give some instructions and to play relaxing music. When you start, the table shows an animation of a ‘soft’ rainbow. After this, colour sections appear on the surface of the table. The child can then pick their favourite colour. A circle appears in the middle of the table. The circle becomes bigger when a child is eating.

If the child eats too fast, the circle does not grow anymore. Another child can

participate but cannot choose their own colour. The colour the first child picks,

becomes the colour of the circle. The same principle holds when multiple people

use the table. Also, with more people, one circle appears in the middle. The

circle grows till the whole table is filled. If more children participate, the circle grows slower. The goal is to fill the table with the circle. When everyone finishes their meals, the table displays firework.

The goals of an ideal system are not all in this system. This is system does have a game like feature. This system also makes sure the food is consumed in a proper time length. With this system, peers are involved in the eating process as well. The parents can take an active role, since the goal is not described in any way. Tests need to be conducted to ensure that this system is involving parents as well. This system does however not provide any information about the benefits of healthy eating. Neither do the children memorise any information about healthy eating.

This system does have features from the co-design sessions. These features are from the users and proxy-users.

3.10 Picking ideas to work on

Due to the time limit of this thesis, it was not possible to work on all the three final ideas. It was possible to work on two ideas. The battlefield in the belly seemed promising, since it meets most requirements. This system does however not have many aspects from the ideating sessions of the (proxy-)users.

The vegetable garden seems promising as well. This system involves more aspects from the ideating sessions than the battlefield in the belly. This system meets most of the requirements as well. The only down side of this system is that it takes more time than the others to make. The growing plants take a lot of time to animate. It is then not possible to make two systems.

The colourful growing circle includes many aspects from the ideating sessions of the (proxy-)users. On the other hand, this system only meets a few of the requirements. However, the co-design method shows that users often know themselves what they want.

The vegetable garden seems the most promising but also the most time

consuming. Thus, I worked on the battlefield in the belly and the colourful

growing circle.

4 Specification

4.1 Ethical implications during a pandemic

Unfortunately, the COVID-19 virus emerged in the Netherlands while I made this report. This virus caused many complications around the world and has influence on this project. Because of the pandemic, the University of Twente set faculty guidelines. The guidelines cover the following.

The University of Twente urgently advised to avoid physical contact or in- direct contact (contact through (prototyped) objects) with individuals. It was prohibited to talk to professionals in the medical field. Conversations, sessions and user tests, therefore had to be done online. No use of physical objects could take place, unless this was done within the household of the user of the physical object.

During this project it was not possible to enter the facilities at the University of Twente. Since the physical Sensory Interactive Table is stationed at one of the facilities of the University of Twente, the table could not be used.

4.2 Requirements of a system

After analysing the state-of-the-art and the literature, I listed a few require- ments.

These requirements are:

• To have a game-like feature in the system

• To provide information about the benefits of healthy eating

• To let parents take an active role during the eating activity

• To let the child memorize the information about the benefits by repetition of the information

• To make sure the food is consumed in a proper time length

• To involve other peers during eating

• To involve ideas of the (proxy-)users

4.3 Requirements of the realisation

Since the physical table could not be used, I listed requirements for the simu- lation of the physical table. I reinterpreted the functions of the physical table, and based on this, made the requirements. These requirements are:

• To be able to eat

• To make sure the food is consumed in a proper time length

• To involve other peers during eating

• Display visualizations on a table

• To use the load cells as buttons

• Make both of the systems as interactive as possible

5 Realisation

This chapter shows the realisation process of the prototype. Firstly, this chap- ter describes the method of the realisation. Secondly, this chapter describes the platform, Unity, used to create the simulations. Thirdly, this chapter describes how the illustrations and animations were made. Finally, the last sections pro- vide information about the process of the implementation of both the systems.

5.1 Method of the realisation

Since the real table was unavailable at that moment due to COVID-19, I had to make a simulation in Unity instead. This simulation imitated the Sensory Interactive Table. The simulation had the same functions as the Sensory Inter- active Table. The simulation showed animations, could detect when someone was eating, and the simulation could use the load cells as buttons. For a more engaging experience, I made a virtual reality experience of the simulation of the table as well.

After this, I made animations using Adobe Illustrator and Adobe After Ef- fects. These animations were for the two systems that came out of the ideation phase.

5.2 Unity

For the implementation of the prototype, the platform ‘Unity’ is used. Unity is a game engine platform which runs on many different devices. This section explains a bit about Unity. I chose Unity for two reasons.

The first reason is the compatibility with the control system of the Sensory Interactive Table. The developers of the Sensory Interactive Table made the control system in Unity.

The second reason to use Unity is its ease-of-use. Due to its user-friendliness, fast prototyping is very efficient. Because of this, fast iterations are easily attainable.

5.3 Unity table

As already explained, the physical table could not be used during this phase.

Because of this, I am improvising with a simulation of the table. I adjusted and added code to create a digital version of the physical table to the control system. This chapter explains how I got a digital version of the physical table.

The following paragraphs explain how this simulation works.

As can be seen in figure 17, there are two different tables. One table, the

displaying table, does not have a technical function. The displaying table is

used to understand where the animations must be. On the displaying table the

animations are projected. The camera that focuses on the animation table sends

the data of the pixels that it captures to the displaying table. Afterwards, the

displaying table sends the information of the data to 199 hex modules. These

Figure 17: Image of the two tables in Unity

modules each have 42 LEDs. The LEDs can be seen as pixels. The colour of the LEDs are then changed accordingly to what the camera ‘sees’. Figure 18 depicts a relatively simple flowchart of the process in the Unity file.

In this way, endless animations are possible. Unfortunately, this simulation does differ from the real table. One main visual issue is that, unlike the physical table, the LEDs do not diffuse. Since the LEDs simply change of colour and do not emit light, the animations and images have a pixel-art vibe. If the LEDs would emit light in Unity, the personal computer needs a powerful graphics card to run smoothly. During the realisation of the simulation, a graphics card of this power is not possible to attain. If the LEDs do emit light, a diffusion of the light can be possible, making the digital table look more like the physical table.

Figure 19: The physical LEDs [12].

One script, already provided with the control system, contains the data for

the placement of the LEDs on the physical table. Researchers of the Sensory

Interactive Table made this script [12]. With this data, the order and placement

of the LEDs on the virtual can be determined. Figure 19 shows the placement