Table of Contents In today's (as well as future) automobiles, in-vehicle infotainment (IVJ) is an inseparable part of he vehicle’s interior and thus also of driver experience. Automotive manufacturers are investing more han ever on its development. For example, Volvo XC90 has seen a notable change during the last ten years in the design of the IVI and driver interaction panel (Figure 1). The same transition can be noted in most of today’s automotive productions. The classic interface with a number of push bottoms and knobs, (one dedicated per function), has shifted into a multifunctional touch screen. This transition is due to several factors, e.g. an increasing number of functions and information being handled through the IVI, the developments of in-vehicle navigation systems, smart phones, multimedia systems, and so forth. Figure 2. IVI with dedicated physical controls (Left- Infiniti), IVI with only one multifunctional touch display (Right-Tesla) The overall aim of the thesis project was to investigate user experience, pleasure and overall user satisfaction with, on the one hand an interface design with dedicated physical controls and on the other hand an interface based on digital elements applied in an IVI system. By physical controls in the interface are meant the mechanical elements of a control panel (e.g. knobs, toggle, pushbuttons, etc.). The digital elements refer to touchscreen solutions for input and output/feedback in a single multifunctional digital display (Figure 2). Figure 3. Overview of the stages of the thesis project The thesis project was characterised as research through design (RtD), i.e. a combination of research, empirical studies and design creation, aimed to answer the research questions and, in the end, propose a design solution (or hypothesis) for the investigated problem. 1.4.1 Literature review A design methodology was required to create a design concept based on user experience. Therefore, ‘ User Centred Design Approach was chosen as the most appropriate model for concept development. Note though that this model does not only cover the actual design phase, but the whole development process! (Figure 5). Jordan proposes four different product pleasures, i.e. Psycho-pleasure, Physio-pleasure, Ideo-pleasure and Socio-pleasure. Psycho-pleasure is interpreted to include aspects such as usability and functionality and Physio-pleasure is defined as elements which are related to human senses. Both these pleasures are considered important for this project. According to Jordan (2000), good human factors (e.g., ergonomics and usability) are no longer enough to reach good design solutions. Good human factors do not indicate an added value anymore, whereas their absence result in disapproval. Jordan argues his point with a hierarchical model of consumer needs, inspired by Maslow’s hierarchy of needs. According to this hierarchy (Figure 6), the bottom layer of the pyramid is functionality, suggesting that a good design should offer appropriate functionality. The second layer of the pyramid is usability. Once the functional needs are satisfied, people start to look for a design that is easy for use. Pleasure is placed at the top layer in the pyramid. Jordan argues that people always seek for added value in their choices. Thus, after the usability concerns are satisfied, emotional benefits start to play a role in decision-making (Jordan, 2000). According to Desmet (2003), emotions are the result of a relation between the person experiencing them and a particular object: e.g., one might be afraid of something, proud of something, in love with someone etc. Object, product, or artefact imply a stimulus in this model. However, the stimulus that evokes the emotion is not necessarily also the object of that emotion. In the present work, the stimulus can be a specific part of IVI (e.g. pushbutton or touchscreen). Desmet and Hekkert (2002) proposed a model which is concentrated on evoked emotions and named it the ‘basic model of product emotions’ (Figure 7). The model represents four factors in user's emotional process: 1) product (as a stimulus), 2) concern, 3) appraisal, and 4) emotion (as a response). Figure 8. Classification of product emotions (Source: Desmet, 2013). Furthemore, according to Desmet (2013), product emotions can be classified into one of the followin; five categories: instrumental, aesthetic, social, surprise, and interest emotions (Figure 8). Figure 10. Early radio and music display systems “The screens are the window to the digital world... screens are new horsepower. Multifunctional displays are becoming the main interface for the driver and passengers with the outside world, we ar witnessing an increase in the use.”’ As more and more car users came to expect music players as standard in their cars, manufacturers worked hard to develop new and exciting in-vehicle music and radio technologies that aligned with how people were consuming music at the time. Some of the most notable innovations of the previous century include in-car record players, 8-track cassettes, car stereos, and in-built MP3 units (Figure 11). The satellite-based Global Positioning System (GPS) was first developed by the US military in the 1970s to provide geolocation and time information to a GPS receiver anywhere on the globe. The first car to boast an in-built navigation system was Toyota’s 1981 Celica model. Dubbed NAVICOM, the system was controlled by a microcomputer, which continuously displayed graphs showing direction and distance to a pre-coded destination (Figure 12). In 1990, Mazda introduced the first ever GPS system for automotive navigational use. Since then, GPS technology has advanced significantly and again has become standard in many new cars in 2019 (Dressekie, 2019). The transition of Volvo cars’ IVI interface over the past twenty years is a clear example of the history of IVIs. This transition is the result of technological developments and user needs which affected both interior design and user experience. Figure 13 shows the shift from an interface with physical controls into multifunctional displays. The same transition can also be seen in most of the today’s cars but with differences in details. In order to analyse the transition and provide a new solution for the possible problems that the users may face, it is necessary to have a clear understanding of the history of these changes. The major trend, however, is to shift into a surface which integrates controls and displays, and whic lemonstrates a seamless surface as an interaction device. A good example of this can be the 1evelopment of BMW infotainment controls over a period of only three years (Breitschaft et al. 2019). This rapid change in design can be seen in Figure 15 from (A) mechanical separated push yuttons with a rotary knob (BMW Group, 2015) through (B) surface integration buttons and nultifunctional knob (BMW Group, 2017) to (C) seamlessly integrated Ul-surfaces (BMW Group, 2018) (Breitschaft et al. 2019). the upper display is usually used for information presentation and output (i.e. navigation map, music list etc.) and the lower display is used as a dynamic input device. In addition, regarding multimodality’, speech and voice command as an interactive mean could increase usability and flexibility. However, several researchers have shown that it can result in frustration, and reluctancy to use after some time. For instance, the user may have problems to find the exact word to control a specific function. Furthermore, users may be reluctant to switch between different modalities due to a perceived increase in cognitive load (Karlsson et al., 2019). Table 2. Different topics, corresponding methods and tools, and theoretical models Also for the analysis different methods and models were used. A thematic content analysis (Rucker, 2016) was performed on the interview data. In addition, a classification of product emotions also known as multi-layered model (Desmet, 2003), the hierarchical user needs model (Jordan, 2000) and impact map (based on a model developed by Volvo cars AB, Domingues, 2017) were used in different stages of the analyses.* In order to make the interview output clearer for the later analysis, the interview questions were separated into three parts. The first part intended to provide an understanding of the respondents’ (i.e. users’) thoughts and experiences regarding the interfaces. The second part consisted of rating scales and was probing the extent to which the respondents agreed/disagreed with the pros and cons that were argued in the Literature Review (Table 1). The third part concerned the transition of interfaces from physical to digital and the way that users had experienced this. The three parts of the interview are elaborated on with examples below. Part 2: In the second part of the interviews, both quantitative and qualitative data was collected with the intention to validate the respective pros and cons that were argued in the Literature Review. Therefore, the participants were asked to consider a number of Likert statement and rate the degree to which they agreed or disagreed with each statement for each type of interface (Figure 19). The respective statements that the user was exposed to (see example in Table 3) were extracted from Table 1 which is a summary of the Literature Review. Other relevant questions were also posed. Figure 19. Presentation format of interview questions of section 2 Figure 20. Basic model of product emotions (case from participant 3M-07) During the interviews, the respondents usually talked about a concern (e.g. "J want to use the interface with gloves") and then connected it to their experience or their anticipated experience with each type of interface. This pattern of conversation enabled using the basic model of product emotions for the analysis. However, in some case, one statement that contained the concern and the emotional response aimed at different aspect of emotion model. As an example, a minimal and clean look can be also interpreted as a social trend and this fact can change the emotional response. The other challenge in analysing the subjective data according to the model of product emotion was the similarity of statements. As an example, many users discussed the familiarity of interfaces during the interview, but since the emotions were not clearly recognizable, it was challenging to judge their actual concern related to familiarity. In this case, familiarity can be interpreted as a description an interface, which has been around for a long time, or an interface, which is similar to the ones in other available devices. The two statements can be interpreted in different ways, and thus also the appraisal and resulting emotions. 3.4.4 Four-fielder matrix Table 8. Overview of the findings; advantages of the interfaces In summary, it can be concluded that all product pleasures affect each other in different ways. It is here argued that there is a complex interdependency between the different pleasures, depending on the user's concerns, behavioural type, and the context of use. Users refer to the pros and cons of interfaces in different ways, since user experience is highly related to their personal experiences and their ideals affected by social norms. Safety is the key factor in the emotional design of interfaces and is the Figure 22. Impact map of user types (the text version is available in Appendix) Figure 25. The combination of both physical and digital elements Figure 26. Different material and tactile in the lower part of the IVI Figure 31. Novel design and compatible with current trends. After each animation, a set of questions were asked to explore the users’ understanding of the concept. A number of statements concerned the advantages of the concept, and the participants were free to agree or disagree with each of them. After each section, the participants could elaborate on their reasoning and talk about their anticipated experience with the interface. At the end, there were several general questions probing the overall experience of the users. An overview of the interview questions is presented in Table 11. Table 11. Overview of Likert scale and evaluative interview questions Table 13. Average ratings per item (n=10) Table 14. Themes extracted from the Interview Study and the Survey. Examples of participants’ Figure 33. Radar chart showing average of ratings of the new concept The number of negative (i.e. cons) responses were significantly less in evaluation of the design concept when compared with the Explorative Study. However, this result can be due to the users’ incomplete perception of the represented concept as it was mentioned many times during the interview study that: "J would like to have a tangible prototype of the concept to assess it more thoroughly" In addition, by comparing the qualitative results from both studies, the design concept, as a visual representation of the pros and cons, included most of the advantages of the existing solutions with few disadvantages regarding each pleasure aspect (Figure 34). Figure 34.Comparison of the different types of interfaces based on a quantitative data analysis Custom made physical and digital HMI for user testing This study was cancelled due to COVID-19 Appendix A. Visuals of primary empirical study Appendix D. Explorative study interview material Appendix F. Implication of multi-layered model of product emotions There were 49 responses to the survey and here only 11 answers are showed as sample data. Appendix I. Sketches of final concept
