Study Guide with article summaries for Applied Cognitive Psychology at Leiden University - 2024/2025

What is interaction design?

In everyday life, products that humans interact such as smartphones, coffee machines, printers, e-readers, game consoles, and so forth are very common. Some of those are easy to use, and enjoyable, while others can be harder to use and can lead to annoyance and frustration.

Interaction design is exactly about this, and answers: how can we help users to positively interact with products and how can we reduce the negative aspects of user experience? It is thus about designing interactive products that are easy, effective, and pleasurable to use from an user’s perspective.

What is the difference between good and poor design?

The authors start with describing two examples of poor designed products: a voice mail system used in hotels and the remote control device.

Voice Mail System

Imagine that you are in a hotel for a week for a business trip. You have left your cell phone at home, and so you use hotel’s facilities. In each room of the hotel, there is a voice mail system. You can find out if you have a message by picking up the handset and listen to the tone. If you hear ‘beep beep beep’, this means that you have a message. Then, to find out how you can access the message, you need to read instructions next to the phone. This instruction says: touch 41. Then, you touch 41 and you hear that you need to enter your Room Number to leave a message. However, you do not have any instructions on how to hear your messages. You look at the instructions again, and you see that you have to touch *, then dial your room number and end with a #. You do so, and then the system replies: “You have reached your mailbox for room 106. To leave a message, type in your password.” However, you do not have a password. You call the reception for help, and the person at the desk explains to you the correct procedure. However, this is a very lengthy procedure… Therefore, you decide to go and get your own phone.

This is thus an example of a poor design, but why is it poor? Well, there are multiple reasons for why we would call this a poor design: it is infuriating, confusing, inefficient, difficult to use, it does not let you know whether there are any messages or how many there are, and the instructions are unclear.

The marble answering machine

The marble answering machine is a bit different from the voice mail system. In this machine, familiar physical objects are used that indicate how many messages have been left. It looks fun and is enjoyable to use. It also only requires one-step actions to perform core tasks. It is simple, but elegant. Lastly, it offers functionality and allows anyone to listen to any of the messages.

This design was created by Durrell Bishop. His goal was to design a messaging system that was enjoyable to use and would also be efficient. However, even though this marble answering machine is elegant and usable, it would not be practical in a hotel setting. For example, it is not robust enough to be used in public places: the marbles could get easily lost or be taken as souvenirs. Also, in hotels, it is important to identify the user before allowing the messages to be played. Therefore, when considering the design of an interactive product, it is important to take into account where it is going to be used and who is going to use it. The marble answering machine is better suited in a home setting than at a hotel, even though at home children could also be tempted to play with the marbles.

Remote Control Device

Unfortunately, remote devices are often poorly designed. Many users find it difficult to locate the right buttons, even for the simples tasks, like pausing or finding the main menu. For some users, it is even more difficult, because they have to put their reading glasses on each time to read the buttons.

However, one type of remote, the TiVo remote control is better designed. The buttons are large, clearly labelled, and logically arranged. This makes the buttons easy to locate and use in conjunction with the menu interface which appears on the TV monitor. The remote was also designed to fit into the palm of a hand, and has a peanut shape. Furthermore, it has a playful look and feel: colourful buttons and cartoon icons were used that are very distinctive, which makes them easy to identify in the dark and without having to put glasses on.

But, why have so many other creators of remote devices failed? Well, the answer is that TiVO invested a lot of time and effort to follow a user-centered design process. For example, TiVo involved potential users in the design process, and got their feedback on everything: how does the device feel in their hand? Where should we place the batteries? They also restricted the number of control buttons and only included the essential ones. The other functions were then represented as part of the menu options and dialog boxes displayed on the TV screen.

How can we know what to design?

When designing interactive products, it is important to consider who is going to use them, how they are going to be used, and where they are going to be used. It is also important to understand what kind of activities people are doing when they use the products. For example, when people are banking online, then the interface should look secure, trustworthy, and needs to be easy to navigate.

Technologies are increasing, and the world becomes suffused with technologies for diverse activities. There are a lot of interfaces and interactive devices available, and they are also very diverse. Interfaces that used to be physical, such as cameras, microwaves, and washing machines, are becoming digital and require interaction design. This is called consumer electronics. There is also another type of costumer interaction: self-checkouts at stores, and libraries in which costumers have to check in their own books. Often, thee interfaces are not friendly. Thus, it is more cost-effective and requires less personnel, but it can lead to frustration for the users: accidentally pressing the wrong button can be frustrating.

The question of: how do you optimize the users’ experience during interaction with a system, environment, or product, so that they support and extend the users’ activities in effective, useful, and usable ways? The authors list some principles that can help in deciding which choice to make:

1. Take into account what people are good and bad at;
2. Consider what might help people with the way they currently do things;
3. Think through what might provide quality user experiences;
4. Listen to what people want and get them involved in the design;
5. Use tried and tested user-based techniques during the design process.

What does Interaction Design entail?

Interaction design is defined as “designing interactive products to support the way people communicate and interact in their everyday and working lives.” It is thus very concerned with practice: how to design user experiences. It differs from other approaches to design computer-based systems such as software engineering. For example, think of someone who works in creating buildings. There are architects and there are civil engineers. Architects think about the people and their interactions with each other and with the house: are there enough family and private spaces? Are the spaces for eating and cooking in close proximity? In contrast, engineers are interested in issues with realizing the ideas. They think about costs, durability, structural aspects, environmental aspects, and so forth. Thus, such as there is this difference, there is also a difference between designing an interactive product (architects) and engineering the software for it (engineers).

What are the components of interaction design?

Interaction design is fundamental to all disciplines, fields, and approaches that are concerned with researching and designing computer-based systems for people. In the book, the figure shows which disciplines and fields these are. The differences between interaction design and these approaches lie mainly in the methods, philosophies, and lenses that they use to study, analyze, and design computers. Another difference is in terms of the scope and problems that they address. For example, the Information Systems approach is about computing technology in domains like business, health, and education. The Computer-Supported Cooperative Work (CSCW) is about finding ways to support multiple people to work together, using computer systems.

Who is involved in interaction design?

Effective designers need to know about users, technologies, and interactions between them in order to create effective user experiences. They need to understand how people act and react to events, and how they communicate and interact with each other. They also need to understand how emotions work, what is meant by aesthetics, desirability, and what the role of narrative in human experience is. Furthermore, they need to understand the business side, the technical side, the manufacturing side, and the marketing side. Thus, it is not surprising that interaction design is often carried out by multidisciplinary teams, in which engineers, designers, programmers, psychologists, artists, and so forth are part of the team. A benefit of this is that many more ideas can be generated. A downside is that it can be difficult to work together, because there are a lot of different perspectives involved.

What are interaction design consultants?

The importance of good interaction designs are acknowledged by many companies. Therefore, there are now many interaction design consultancies. These include companies such as Cooper, NielsenNorman Group, and IDEO and also more recent ones. IDEO is a big company that has developed thousands of products, for example the first mouse used by Apple.

What is the user experience?

The user experience (UX) is very important in interaction design. UX refers to how a product behaves and is used by people in the real world. Every product that people use has a user experience: newspapers, ketchup bottles, and so forth. It is about how people feel about a product and how much pleasure and satisfaction they derive from it. It is about the overall impression of how good it is to use, to how nice it feels in your hand.

An important point is that user experience can not be designed: one can only design for a user experience. Some designers say UXD instead of UX. The ‘D’ refers to encouraging design thinking which focuses on the quality of the user experience rather than on the set of design methods to use.

There are thus many different factors that interaction designers need to take into account. Unfortunately, there is no unifying framework that can be used, but there are conceptual frameworks, tested methods, guidelines and other relevant research findings, which will be described.

According to McCarthy and Wright, there are four core threads that make up our holistic experiences: sensual, emotional, compositional, and spatio-temporal:

1. The sensual thread. This refers to our sensory engagement with a situation. It involves the level of absorption people experience with technological devices and applications. Think of computer games, smartphones, and chat rooms, in which people are highly absorbed in their interactions at a sensory level: they feel thrill, fear, pain, joy and comfort.
2. The emotional thread. Research on this thread is about how emotions are intertwined with the situation. For example, a person may become angry with a computer because it does not work properly. Emotions also refer to judgments about value: when someone purchases a new phone, one might be drawn to the ones that are cool-looking. However, they may experience turmoil because these are the most expensive phones.
3. The compositional thread. This thread refers to the narrative part of the experience, and the way a person makes sense of it. For example, when shopping online, sometimes the options are very clear to people, but sometimes it can also lead to frustration. For example, people might ask themselves: “What is this about?” or “What happened?”. This thread is thus about the internal thinking that occur during experiences.
4. The spatio-temporal thread. This refers to the space and time in which our experiences take place and their effect on these experiences. There are different ways to talk about this, for example we talk of time speeding up, slowing down, and we talk about space in terms of public and personal space, and for example needing one’s own space.

These threads can be used as ideas to help designers think and talk more clearly about the relationship between technology and experience.

What is the process of interaction design?

The process of interaction design involves four basic activities:

1. Establishing requirements
2. Designing alternatives
3. Prototyping
4. Evaluating

These activities are used to inform one another and they are also meant to be repeated. For example, one can measure the usability of what has been built by looking at how easy it is to use. This can provide feedback about that some things need to be changed, and that certain requirements are not met yet. It can also help to elicit responses from potential users about what they think and how they feel about what has been designed. This evaluation is really important in interaction design, and is needed to make sure that a product is appropriate. As important as it is to involve users, it is also important to understand people’s behaviour. This knowledge can help the designers to create better interactive products. Learning about people can also help to correct incorrect assumptions that designers have. For example, it is often assumed that old people want bigger texts, because of poorer vision. However, studies have shown that people in their 70s, 80s and older have good vision and are capable of interaction with standard-size information. It is also important to be aware of cultural differences. For example, the time and date in different countries: in the USA, date is written as month/day/year (05/26/1998), and in other countries it is often written as day/month/year (26/05/1998). Designers can also use contrasting designs, in which different colors, images and structures are provided to appeal to people in different countries.

What about interaction design and the user experience?

Before developing an interactive product, it is important to understand what the goal of this product will be. Is the goal to make the users more productive? Is the goal to create a learning tool that is challenging and motivating? The authors suggest to classify the goals in terms of usability and experience goals.

What are usability goals?

Usability is defined as making sure that the interactive products are easy to learn, effective to use, and enjoyable to use from a user’s perspective. It is broken down into these goals:

• Effective to use (effectiveness);
• Efficient to use (efficiency);
• Safe to use (safety);
• Having good utility (utility);
• Easy to learn (learnability);
• Easy to remember (memorability).

These goals are often operationalized as questions. Through answering these questions, designers can be alerted very early on in the design process to potential problems and conflicts. An example of a good question is: “How long will it take a user to figure out how to use the most basic functions  for a new smartwatch; how much can they capitalize on from their prior experience; and how long would it take a user to learn the whole set of functions?”. Simply asking: “is the system easy to learn?” is not a good question.

What are user experience goals?

There are a lot of different experience goals. These goals include emotions and felt experiences, and are divided into desirable and undesirable ones. This is shown in Table 1.1. Examples of desirable aspects are: satisfying, helfpul, ful, and undesirable aspects are: boring, unpleasant, frustrating.

What are design principles?

Design principles are generalizable abstractions which are intended to orient designers toward thinking about the different aspects of their designs. A common example is feedback: a product should incorporate adequate feedback to the users to ensure that they know what to do next in their tasks. Another one is ‘findability’, which refers to the degree to which a particular object is easy to discover or locate (navigating a website, finding the delete image option on a digital camera).

These principles are derived from theories, experience, and common sense. They are prescriptive: they thus prescribe what designers should provide and what they should avoid (do’s and don’t’s).

The authors describe the most common design principles: visibility, feedback, constraints, consistency, and affordance.

Visibility

Think back to the voice mail system: the voice mail system made it unclear as to how many messages there are, while the answer machine using the marbles made it very clear. Norman (1988) uses an example of the controls of a car: the controls for the different operations are clearly visible (indicators, headlights, horn). This makes it easier for the driver to find the appropriate control. When things are not visible, it makes it harder for users to use them. Nowadays, a lot of products do poor on this principle: for example think of the sensor technology used in bathrooms. When you washed your hands and there is a sensor technology for drying your hands, it can be sometimes difficult to know where to place your hands in this drying machine.

Feedback

Feedback is defined as sending back information about what action has been done and finished. There are different types of feedback for interaction design: audio, tactile, verbal, visual, and combinations of these. It is important to decide which combinations are appropriate for different kinds of activities.

Constraints

Constraining users refers to determining ways to restrict the user interaction that can take place at a given moment. There are different ways to achieve this, and a common example is to deactivate certain menu options, thereby restricting the user to actions permissible at that stage of the activity. This prevents users from selecting incorrect options and reduces the chance of making a mistake. This can also be incorporated in the physical design of a device: the external slots in a computer have been designed to only allow a specific cable or card to be inserted in there.

Consistency

A consistent interface is one which follows rules, such as the same operation to select all objects. For example, always clicking the left mouse button to highlight a graphical object. Consistent interfaces are easier to learn and use. This can be more difficult to achieve in complex interfaces.

Affordance

Affordance means that people are given hints about how to use the product. For example, a mouse button invites pushing (clicking) because it’s constrained in its plastic shell. When products are affordable, it makes them easier to interact with. Other examples are a door handle which affords pulling, and a cup handle affording grasping. Norman (1999) suggests two kinds of affordance: perceived and real. Physical objects have real affordance (a cup has actual handles). This means that it does not have to be learned. Interfaces are screen-based and do not have real affordances. Instead, screen-based interfaces are said to have perceived affordance, which can be learned.

What is this article about?

The article by Theeuwes (1992) is about the ability of parallel stage visual processing to selectively guide the attention. Visual information processing consists of two stages. First, the early, preattentive stage, operating without capacity limitations. The attention cannot be selectively drawn to one certain stimulus. The second one, limited-attentive-capacity stage can only deal with one or few items at once. Hereby, the nature of a stimulus makes a difference. For example, when searching for a certain color, the form did not interfere, and when searching for a certain form among stimuli, the color did not interfere.

Different theories describe the processes. One theory describing a bottom-up activation, indicating that parallel stage is followed by focal attention. Other theories focus on top-down processing, indicating that visual attention is always influenced by the knowledge about the target.

In the experiments of this study, the question of whether selectivity can be obtained when not only the stimulus dimension is known (e.g. that the target has a unique color), but also the exact feature value (e.g. the target is green). In order to answer this question three experiment has been conducted.

What has been done in experiment 1a?  

The first experiement had four conditions. The non-distractor color condition, green circles, as a unique color, was embedded in red circles. In the distractor color condition, one red circle was a red square. The non-distractor form condition consisted of green circles and green squares. The distractor form condition was one of the green squares red.

During the tasks, 5,7 or 9 items were located around a fixation point. The participants in the form condition, and those in the color condition received both conditions, with 144 trials each. Each participant should search for the target and press the fitting response key. Speed and accuracy was measured.

Results and Discussion

The results showed if the target item differs in color, the form of the item does not interfere with the reactivity. However, if the form differs, the reactivity is slowed down. Selectivity for color seems to depend on bottom-up activation. Selectivity for top-down activation has not been found. Those results align with previous studies.

What has been done in experiment 1b?

The method and procedure were similar to the conduction of experiment 1a. Eight participants joined 144 trials. The form condition was used, participants had to look for green circle within green squares in a non-distractor and in a distractor condition.

Results and Discussion

Results showed that a top-down control is not possible and practice does not improve selectivity.

What has been done is experiment 2?

The difference in selectivity for form and for colors was tested in experiment 2. In total 16 participants joined the experiment, with eight participants assigned to the form condition and eight to the color condition. The focus of this experiment was on asymmetric selectivity

Results and Discussion

Results have shown that form with is an easier target to select attention on, whereas the search for a different color is more difficult if forms are the same.

How can the findings of all three experiment be summarized?

The goal of the three experiments was to understand the extent to which the first stage, the preattentive stage, can selectively guide attention. Previous studies found that stimulus discrimination towards a dimension does not occur. The current study found that stimulus discrimination towards a feature (form or color) does also not occur. Bottom-up processing seems to be common process. However, this does not exclude a possibility of top-down processing within the first stage.

What is this article about?

The focus of this article is on Human Machine Interface (HMI) as main communication tool between any vehicle and the human driver. HMI includes all kinds of displays, visual and auditory, all vehicle controls that provide the communication and feedback between vehicle and driver. HMI is from even greater importance in fully automatic cars, providing mutual understanding and trust. In automated vehicles, HMI has to inform and support the human about its capabilities.

In this article, goals of HMI will be established, based on “ten challenges”, of Klein et al. (2004), which are based on the four principles of proper human-agent activity, The four principles are an agreement that actors will work together, actors must be mutually predictable in their actions, actions must be mutually directable and a common ground has to be maintained. A proposal for fully automated vehicle HMI-system will be designed in course of this article.

What should be the goals of HMI for automated vehicles (AV)?

• Provide understanding of AV capabilities and status
• Encourage correct calibration of trust
• Stimulate appropriate level of attention and intervention
• Minimise automation surprise
• Provide comfort to human user
• Be usable

In the following paragraphs, each aspect its importance for HMI is evaluated.

Provide understanding of AV capabilities and status

It is crucial for the user of an vehicle to understand which function are being provided. In an AV, users only have to understand journey-related requirements. However, a user might also want to know if the AV controls aspects a driver would usually control, such as lane keeping, ACC and overtaking another vehicle. Without indication and comprehension of different task and abilities of the AV, the user can easily be confused, which might result in mode errors, such as accidents.

In order to avoid that, a visual interface usually shows whether or not a function is activated, for example showing with colored lines whether or not the lane is properly detected. A head up display can be used to decrease the eyes-off-road time.

Encourage correct calibration of trust

Trust in a vehicle is crucial for the user to buy it. Maintaining trust is crucial, since it is difficult to regain once its lost. Studies have shown that users of AV tend to pay less attention to the road, despite the possibility that the system might fail.

Calibration of trust indicates to provide the user with the accurate knowledge about the system’s capabilities. Hereby, trust is not a unidimensional concept, but can be more seen as a fluid concept and level of trust in AV depend on the driving situation the user is in at the moment, but also to the users characteristics and experience with AV.

For a correct calibration of trust, HMI should guide the driver in actual driving conditions and under the setting used in this moment.

Stimulate appropriate level of attention and intervention

An appropriate level of attention and intervention is required to ensure safety. If a AV requires some level of control from human driver, more attention is given, which allows a safe intervention when needed. Since the system might fail, it is always required to be attentive as a user of an AV.

Eventhough it seems reasonable to be attentive in an AV, this is not always the case. The more trustworthy a systems seems, the less attention is being paid to. If the AV can keep the vehicle in the lane, why would the user see any necessity to keep their hands on the wheel?

In order to provide and maintain an appropriate level of attention and intervention, is to inform the users that if the system is known to have limitations and that the user should monitor the outer world. This also includes having the foot on the pedal and hands on the wheel, especially while driving through curves. In case systems are already known to be unsafe in certain situations, the system should also be capable of detected those situations and to inform the user

Minimise automation surprises

Automation surprise describes when the driver notices that the systems actions are inconsistent with their expectation. This can lead to absence of expected action, where the system does not perform the expected action, or to the presence of unexpected action, where the systems perform an action that does not correspond with what was expected. This might lead to danger, since the user is not aware of the abilities and capabilities of their system.

The goal of HMI is it to provide the user with observability, predictability, directability and timeliness. Observability includes the ability of the driver to understand the system status, because signals has been provided by the system through the HMI. Predictability indicates that action should be observable enough for drivers to plan their actions accordingly. HMI should predict whether or not it can or should be interfered in that situation. Further, HMI should accept, use and interpret user input to influence and be influenced to the best joint performance (Directability). Next, any unexpected situation should be signaled early enough (Timeliness).

Provide comfort to human user

Physical comfort

A main concern regarding physical (dis)comfort is motion sickness of user, due to incongruence between what users are doing and what they feel. It can be avoided by adjusting the behavior of the AV and by locating HMI in a good positions, or by adding additional displays.

Psychological comfort

This aspect related to state of well-being and minimization of stress. It is enhanced by making the driver feel at ease and by having trust and confidence in the system, which in case in increased by more often use of AV.

Usability

Usability refers to effectiveness, efficiency and satisfaction of a system. In case of AV, the usability depends on the user, the system and the current given situation. HMI can support usability by not differ too much from what the user is used to already and be more consistent to what already exist.

What does all of that mean for the implications for HMI design?

HMI is an important factor for increasing safety and comfortability in a joint cognitive system between driver and AV, to reach the best possible performance. It is important to understand how the described aspects are related to each other, and should be implemented in design of HMI.

Provide required understanding of the AV capabilities and status (minimize mode errors)

The HMI display should provide the user with an overview and understanding of what the AV is doing.

Engender correct calibration of trust

HMI should include and support observability, predictability, directablility and timeliness.

Stimulate appropriate level of attention and intervention

 HMI should make sure that driver is paying attention, and the level of attention, is fitting with the level of automation of the vehicle.

Minimise automation surprises

HMI should communicate any situation where the system is not working reliable anymore immediately.

Provide comfort to human user

The HMI display(s) should be located in a position to minimize additional head movement for the driver.

Usability

HMI should be designed in standardized ways, include for example the same symbols for automated driving, for lane keeping, for potential failure of the system.

How can the information of this article be concluded?

Even within the use of AV, it is important for users to understand the capabilities and possible inabilities of their AV. HMI is used to describe and support user in understanding of their vehicle and should increase a joint communication between AV and user.