I'm revisiting a grad school project on appliance interface design, looking at my ideas from a more experienced perspective. How might the design change if I had done this project several years later? Over the next couple of weeks I'll be reviewing my work on this project and how my views have changed since entering industry. This post is my report from a project advised by Anind Dey from Carnegie Mellon.
Kitchen Appliance Interface Design: Usability vs. Marketability
Over the past several years, kitchen appliance design has trended toward over-designed interfaces, cluttered with buttons for features most users either do not understand or choose not to use. Extra features are used to market appliances as more superior than previous models or other brands, but we questioned whether having such an abundance of options actually meets user need. In particular, we wanted to find the answer to the following questions:
- Which features of common kitchen appliances do users really need and which do they frequently use?
- Do shoppers consider an appliance that has more features to be better than one that has fewer?
- Which features do users absolutely need?
- What is the balance between a usable product and a marketable product and how does that affect the design of an entire product line?
- If a kitchen appliance is simplified to provide only commonly used features, will buyers stray away, thinking the product is inferior, or would it be more marketable as a “classic” design?
Our goal was to develop a line of eight kitchen appliance interfaces, including a blender, toaster oven, microwave, countertop grill, refrigerator temperature controls and ice/water dispenser, oven range, dishwasher, and coffee maker that balance continuity, marketability, usability, and aesthetic quality. The challenge was in creating not just one interface, but in producing several interfaces for completely different products while maintaining a similar appearance and working toward better usability of each by reducing extraneous features, redesigning users’ “must haves”, and working toward a more “classic” design.
Design Process
We applied several methods to evaluate current kitchen appliance designs and to use that knowledge for generating new ideas: competitive analysis, analysis of a focus group session, heuristic evaluation of initial prototypes, as well as paper and software prototyping.
Competitive Analysis and Market Research
We spent the first several weeks on this project performing significant background research on kitchen appliances currently on the market, visiting consumer and retail Web sites, and browsing large warehouse stores. While “shopping”, we noticed that with large appliances, higher end and lower end brands are generally grouped separately. The more expensive brands offered more features, often meaning significantly more buttons, dials, and knobs, and looked more futuristic. There were oven ranges and dishwashers with so many features it was unclear how the average buyer would learn to use them. Not all high end appliances appeared to be over-designed. In particular, Jenn-Air TM, though ranging from $1200-$5600 in price, offered a reliable, powerful stove with mainly essential, centrally located features.
Lower end appliance brands, such as Galaxy and Tappan, offered fewer features but they were designed to be “walk up and use” without having to read a manual. They were simple and functional. However, buyers who can afford it are more likely to buy more expensive appliances. The brand image of lower end companies is that they are not reliable in the long-term and would not be a show piece for buyers looking to display a nice product in their kitchen.
Most brands offered varied choices in appliance functionality and appearance. These range from the very functional to space-age appearing styles. The more functional appearing the appliance, the less expensive it was. Most of the basic, necessary features offered remained the same across products however. People pay more for an attractive appliance that can be displayed proudly in the kitchen. This finding led to other questions: How many people leave small appliances out on the counter? Do buyers select a more expensive appliance just for show? Is there a way to design attractive kitchen appliances with simple appearances that could be known for brand reliability, but not be considered “high end”?
Focus Group
To answer these questions, we conducted a focus group with 6 people (4 women and 2 men), where we discussed kitchen appliances on the market, which brands are trusted most, what features are commonly used, and the overall likes and dislikes of current designs. While 2 participants were under the age of 25 and not homeowners, they provided valuable feedback on the purchase and usage of small kitchen appliances, such as microwaves and toaster ovens, and their experiences with large appliances in the households they grew up in. Homeowner participants discussed the purchase and brand selection of large appliances like dishwashers and refrigerators.
It was clear that brand image was a major factor in kitchen appliance selection. Participants wanted appliances to last a long time and felt that two brands in particular held this reputation: Kenmore and Kitchen Aid. Several participants pointed out that they have had the same Kitchen Aid mixer and Kenmore stove for 20 or 30 years, often handed down from relatives.
Participants in the focus group named features that they absolutely must have. For example, because they agreed that an easy to clean appliance was high priority, a self-cleaning feature was considered a requirement for many of the appliances. Other “must-have” features dealt with issues of feedback and control. For example, desired oven features included a preheat indicator light and multiple burner temperature setting choices. For the microwave, they were popcorn and defrost buttons. Participants also wanted timed coffee brewing, and dishwasher delay start functions.
The group also agreed that it was more important for an appliance to be easy to use, than to look attractive. This seemed to conflict with designs currently on the market. Those which are easier to use seem to be less expensive brands, and are often the brands deemed to be of lesser quality.
Paper Prototyping
Taking into account the data gathered from the focus group, initial designs were hashed out over several sketching sessions. When iterations seemed to match well with user needs determined from the focus group, 9 test users (3 female, 6 male) were recruited for 2 rounds of paper prototyping of eight kitchen appliances. Some of these users had also participated in the focus group and were eager to see how the design process would progress. Test users were asked to complete several simple tasks using 4 to 8 appliance interfaces while thinking out loud their opinions, concerns, questions, and completion steps. These tasks varied by appliance and were designed to be similar to real life situations including making popcorn using a new microwave and dispensing a glass of ice water.
Paper prototyping posed several problems in evaluating the design ideas. We wanted to implement touch-sensitive control surfaces for several reasons. The primary motivation for redesign was to create innovative appliance interfaces that balance usability and marketability. Our focus group showed that users looked for easy to clean and long lasting appliances, but buyers are first attracted to the look of an appliance . To achieve a truly easy to clean appliance interface, we aimed for a smooth surface, eliminating dials and knobs from all the appliances. The decision to design for touch-sensitive controls also feeds our interest in creating something that is not commonly available on current kitchen appliances. It was difficult for users to understand appliance functionality on paper. It was not always clear which controls were buttons or toggles and which were simply labels. Paper prototyping did, however, help identify problems in label wording, interface layout, and design features that were unnecessary or too complicated, as well as features missing from our initial designs.
Users had significant difficulty understanding the order in which to operate the controls for the coffee maker, dishwasher, and oven range. For example, they felt there were too many choices to make when trying to set the auto-brew feature of the coffee maker and spent considerable time studying the interface and considering which controls might work.
Another problem at this stage showed to be confusion on the operation of “one-touch” buttons. For example, some users were accustomed to microwaves with a popcorn button that immediately begins the cooking process when pressed. Others expected to press the start button after pressing the popcorn button. We felt users would learn quickly how button works, especially when testing with higher fidelity prototypes that provide clearer feedback.Heuristic Evaluation
A heuristic evaluation was conducted on iterations designed in Adobe Illustrator® between our sketched and Visual Basic prototypes. The biggest concern that became apparent during this cycle of evaluation was consistency among the appliances. In order to represent a brand or line of appliances, colors, font selections, layout, and widget style needed to be consistent across all eight prototypes.
Visual Basic Prototyping
Four users (all older than 25, 3 female) were recruited for a round of Visual Basic (VB) prototyping. As with the paper prototype tests, participants were asked to complete several simple tasks using four to eight appliance interfaces while thinking out loud their opinions, concerns, questions, and completion steps.
The software provided much more feedback to test users than paper prototyping could, which afforded more accurate responses. It was clearer to users how to work the appliances, and fewer problems resulted. While the question of how to operate the novel touch-sensitive controls remained throughout the design process, users were able to quickly learn how the controls worked and felt comfortable with the interaction after testing the entire line of appliances.
Results
One of the key issues we wanted to address was to design an entire line of kitchen appliances that is easy to use but still offers the required functionality to make it a marketable brand. A major challenge in this was handling design problems that, if changed significantly, could also impact whether the line could be seen as a true brand. The three most significant issues we addressed were usability, ease of cleaning, and having design consistency across all appliances.
Usability
In the end, the only significant usability problem still visible in user tests had to do solely with touch-sensitive heat and speed settings on the blender, toaster oven, countertop grill, and stove top. Users consistently wanted to set the heat or speed before turning the appliance on, however in talks with users and after testing multiple appliances, it was determined that users would quickly be able to learn the proper order of operations without wasting too much time or exceptional difficulty. Some concerns still remain that novice users actually purchasing one of these appliances may fear they have a defective product if they aren’t able to quickly figure it out.
Easy to Clean
We eliminated traditional mechanical widgets from all appliances and replaced them with a flat, touch-sensitive panel. Buttons on each appliance are raised areas but the material is still flush with the rest of the surface. There are no crevices where food or drink could seep into, which could lead to bacteria build-up and make it hard to keep clean.
Consistency
Consistency is the key to establishing the line of appliances as a brand. While we focused first on the usability of each individual component, we improved consistency during the Adobe Illustrator iteration. We selected a medium-blue color to be used at the top of each appliance control panel, as that color invokes positive and calm feelings . Shoppers are less likely to postpone purchases in a blue environment. We also used one main font for the label text (Myriad) and the appliance headings (JunebugStomp). These appear both fresh and exciting, but are also easy to read.
Lessons Learned
Low prototype fidelity may not always provide accurate user test results. One of the biggest concerns we have is that potential buyers may stray away from a stovetop that is controlled by touching a finger to the potentially hot surface. While we would expect to use materials that would remain cool to the touch for this part of the design, users may not want to risk touching near a hot burner. Although during paper prototyping, users did not express concern for their own safety (although the safety of cats did come up), and many actually said they would not have personal concerns using this design. During VB prototype testing, this concern did come up with a user mentioning she would rather have more space between the burner and the controls. The only way to really know how users would react to a touch-sensitive burner control on the same plane as the cooking area would be to create a real, physical prototype.
Users want easy to use appliances but buyers are initially attracted to aesthetics. Although focus group participants explained the importance of brand reliability, from a marketing perspective, it is also important for appliances to be aesthetically pleasing to attract consumer attention . There are 2 reasons for this. A small kitchen appliance that looks good enough to keep on the counter has the potential of being seen by visitors. Like the adage, “do as the Joneses do”, the possibility of a neighbor, friend, or family member noticing and liking the look of an appliance located in a typical kitchen environment instead of in a store surrounded by many other models, is strong. People also often spend a lot of money to design a kitchen. Having appliances they consider “beautiful” or “cleanly designed” can enhance the overall look of the space. Having more features does not make a better brand. During the focus group, participants were adamant that Kenmore was a better large appliance brand, and Kitchen Aid a better small appliance brand. The reason explained was that these companies have been around for decades and make products that often last for decades themselves. Reliability was extremely important. Better brands were those that focus group participants trust to last a long time.
Conclusion
To investigate issues of usability and marketability in kitchen appliances, we spoke with appliance owners in a focus group setting, and designed and tested several design iterations for a refrigerator temperature control panel and ice/water dispenser, coffee maker, oven range, blender, toaster oven, microwave, countertop grill, and dishwasher. The conclusion we came to was that the balance of usability and marketability comes in being sure that the essential feature requirements are met with each design, without cluttering the interface with controls that are rarely used by only a select group of potential customers. In addition, appliances must have strong visual appeal to stand out from other brands and to aid an owner’s impression management.
Citations
[1] Brandl, P. How and Why They Buy. Appliance Design 53, 5 (2005), 56.
[2] Bellizzi, J.A. and Hite, R.E. Environmental Color, Consumer Feelings, and Purchase Likelihood. Psychology & Marketing 9, 5 (1992), 347-363.
[3] Rodrigue, C.S. and Biswas, A. Brand alliance dependency and exclusivity: an empirical investigation. Product & Brand Management 13, 7 (2004), 477-487.
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