This post is the first in a series of 16, originally published on April 15th, 2006 as the “UXE White Paper: User Experience Engineering Essentials."

I coined the term "User experience engineering (UXE)" to describe a structured research, design, and evaluation process whose goal is to make user interactions with a product or service easy, efficient, and enjoyable. It evolved from usability engineering and applies psychological principles and methodologies.

Our experience of a product can be divided into three primary levels: visceral, behavioral, and sociocultural. The visceral level is an immediate and instinctive reaction that is greatly influenced by the appearance of the product. The behavioral level develops through our interaction with a product and is greatly influenced by its usefulness and usability. The sociocultural level appeals to self-identity and personal symbolism. UXE addresses these three levels of experience in product and service development.

The user experience is engineered in five iterative phases:

1. Business objectives for UXE. Define the business or organizational objectives for the UXE effort, so UXE produces maximum impact.
2. User research. Collect targeted data on users (prospective or actual), their tasks, and their environment through observation and discussion.
3. UX requirement analysis. Define specific product and UX requirements for areas where business objectives and user research overlap.
4. UX design. Develop a series of increasing detailed models or prototypes (conceptual, architectural, interactive, aesthetic), iteratively evaluating and redesigning each type before going on to the next.
5. UX evaluation. Evaluate and test models and prototypes to generate new design ideas and to determine whether UX requirements have been met.

Each phase has its own work products that capture knowledge generated in that phase and help designers apply the knowledge in the next phase.

Most major technology companies including IBM, Microsoft, Samsung, eBay, Amazon, and Apple have invested heavily in UXE. UXE is also rapidly making inroads into established industries, with companies like GE Healthcare, Whirlpool, and Procter & Gamble reaping huge product successes from it. Despite this momentum, there is still room for improvement. A review of 700 corporate Web sites, gave only 3% a passing grade, and most high-tech gadgets remain too hard to use. This means UXE can still provide a competitive advantage to any company that chooses to invest in it.

Best-practice companies invest from 10% to 19% of the total product development project budget in UXE, which offers an impressive return on investment (ROI) of $2 to $100 for every $1 invested, accomplished in four main ways:

1. Increasing sales by improving product appeal, making e-commerce sites more usable, stimulating cross-channel activity, and improving customer retention.
2. Enhancing productivity by increasing employee efficiency.
3. Decreasing costs of development, maintenance, support, and training.
4. Reducing risk of project cancellation and litigation.

For maximum ROI, UXE methods must be used from the beginning of the project so project requirements are based on marketable user needs and development efforts achieve maximum efficiency. In today’s networked, interconnected marketplace, consumers will shift their loyalties to the companies and brands that can provide them with the user experience that they value, so UXE methods offer a competitive advantage with immediate tactical value and long-term strategic benefits.

• Series Introduction
• What Is User Experience Engineering?
• What Are The Levels Of UX?
• How Is User Experience Engineered?
• Who Uses UXE?
• Why Use UXE?
• When To Use UXE?
• User Experience Articles and References

User experience engineering (UXE) is a structured research, design, and evaluation process whose goal is to make user interactions with a product or service easy, efficient, and enjoyable. UXE methods can be and are applied to the development of virtually any product or service, from mops [142] to surgical devices [98], to retail environments [32]. However, the term is most frequently applied to digital products such as software, Web sites, and electronic devices. This paper focuses primarily on UXE as it is applied in the digital context.

UXE has been influenced by the fields of human factors and ergonomics and is considered a practical application of research in human-computer interaction [95]. It evolved from, and shares much in common with, usability engineering [78; 866] whose central concern is product usability, defined in ISO 9241 as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction” [18]. A user’s experience of a product includes its usability and extends to the user’s emotional interaction with the product and the organizational channels that promote, supply, and support it. UXE addresses these additional elements. User experience professionals typically work closely with marketers, software engineers, graphic artists, industrial designers, customer support staff, and other professionals as good user experience results from a team effort.

If engineering is the application of scientific knowledge to practical problems, the science from which UXE draws most of its primary theoretical and methodological inspiration is psychology. UXE applies experimentally validated principles [22; 84; 95] from the fields of sensation, perception, and cognition [20], emotion and motivation [92], as well as social psychology [38; 39]. UXE also adapts research methods from experimental psychology [116] and related social sciences such as anthropology and sociology [81; 140].

Our experience of a product can be divided into three primary levels [92]: visceral, behavioral, and sociocultural (elsewhere referred to as reflective [92] or symbolic [107]). The visceral level of experience is an immediate and instinctive reaction that is greatly influenced by the appearance of the product. The sleek lines of a classic automobile appeal to this level of experience. The behavioral level of experience develops through our interaction with a product and is greatly influenced by its usefulness and usability. A cup holder in an automobile need not be attractive because it is useful. If you drive your car along a winding road and can drink your beverage without spilling it on yourself, it is usable. This combination of usefulness and usability appeals to the behavioral level of experience. The sociocultural level of experience appeals to self-identity and personal symbolism and is influenced by cultural norms. Driving a mini-van says something different than driving a sports car. Most importantly it says something to the driver, it is an act of self-definition [36; 108].

• Executive Summary
• What is User Experience Engineering?
• What Are The Levels Of UX?
• How Is User Experience Engineered?
• Who Uses UXE?
• Why Use UXE?
• When To Use UXE?
• User Experience References

Although certain personality traits moderate visceral influences [17], the visceral level of experience is largely pre-wired and biologically determined. We have evolved visceral responses that attract us to objects and environments that provide a survival advantage and repel us from those that pose a survival risk [66]. We like flowers because they signal forthcoming nourishment, vistas because we feel safer if we can see danger coming, and lakes and rivers because the water they contain quenches our thirst and implies additional food resources [5]. We like symmetrical features in a potential mate because they suggest health and therefore fertility [19]. We dislike dark environments and sudden loud noises because they predict danger [48]. However, we can learn to like some stimuli that are naturally aversive. For example, we can acquire a taste for bitter or spicy foods if we are regularly exposed to them and receive social reinforcement for their consumption [143].

Visceral preferences are based on our sensory impressions and are largely influenced by the aesthetic qualities of the perceived object. They are immediate, emotional, and pre-cognitive. Neurophysiological evidence shows that emotionally evocative stimuli directly impact the amygdala—the part of the brain responsible for emotional experience—without involving the higher cognitive centers of the cerebral cortex [e.g., 70]. When we see or hear something that is potentially pleasurable or threatening, we become aroused—measured as increases in heart rate, sweat, and startle responses [14]—and are either drawn to the stimulus or away from it, all this before we can consciously analyze or sometimes even notice the stimulus. Based on our first impression we either like something and want it or do not like it and want to avoid it. This first impression biases any subsequent cognitive evaluation, sometimes reducing a logical analysis of product benefits to nothing more than a justification for a preference already formed at the visceral level [143].

Since the emergence of industrial design in the early 1900s, aesthetic appeal has been used as a powerful marketing tool [35; 101]. Apple Computer’s 1997 launch of the iMac is a recent example of a successful product that relied primarily on aesthetics to drive sales. The iMac’s curvy all-in-one form factor and colorful translucent casing stood in stark contrast to the bland putty-colored box-like computers available from PC manufactures, leading one reviewer to say “Wow! I gotta get me one o’ those right now!” [117, p. 22]. Brisk sales in the first year increased Apple’s market share by 66% (from 3.5% to 5.3%) [138], this despite the fact that iMac offered only incremental functional improvements over earlier models.

While the iMac is one of many examples in which compelling aesthetics led to a popular consumer product [35], the conventional view of the importance of the appearance in business-to-business, industrial products has been that “business products do not necessarily make anyone look or feel better, and they generally do not have significant aesthetic value” [15, p. 123]. However, this perspective has been shown to be incorrect: a study of engineering, marketing, and purchasing personnel who evaluated industrial products like motors, oscilloscopes, and pumps preferred those with attractive visual aesthetics and in some circumstances the influence of visual ascetics on purchase intentions exceeded that of product performance and price [141].

The influence of aesthetic appeal extends to Web sites and software. In a study that looked at user’s first impressions of Web pages, pages high in the subjective attribute of “beauty” gave the best overall impression [118]. Another study measured how persistent users were in browsing for information and found users significantly more persistent on sites whose color scheme they rated as attractive [82]. And in several studies of software for automated teller machines [64; 128; 129], industrial control [52], and MP3 players [51], users who perceived the software as beautiful and appealing also perceived it as useable during their initial evaluation. Perceived usability is important because software that is perceived to be usable is likely to be accepted and adopted [29; 133]. In some cases the initial perception of usability persists even after users interact with the software that is designed to be hard to use [129].

If the visceral level of experience is so compelling and colors perceptions of behavioral attributes like usability, is it the only level of experience we should be concerned with? It is true that visceral experience greatly influences our first impressions and biases our subsequent judgments. However, first impressions do change: for example, one study showed that users modified their original evaluation of the software usability after interacting with it, showing that the behavioral level of experience is influenced by product interaction [51].

• Executive Summary
• What Is User Experience Engineering?
• What Are The Levels Of UX?
  • The Visceral Level
  • The Behavioral Level
  • The Sociocultural Level

• How Is User Experience Engineered?
• Who Uses UXE?
• Why Use UXE?
• When To Use UXE?
• User Experience References

Designing for the visceral level of experience attracts attention and may motivate a customer to buy a product. But consider what can happen when the product does not deliver at the behavioral level what it implies at the visceral:

Shortly after midnight, a resident of a small town in southern California called the police to report hearing a man inside a house nearby screaming “I’m going to kill you! I’m going to kill you!” Officers arrived on the scene and ordered the screaming man to come out of the house. The man stepped outside, wearing shorts and a Polo shirt. The officers found no victim inside the house. The man had been yelling at his computer [39, p. 89].

The description above, based on a police report from Seal Beach, California, illustrates the intensity of frustration that can develop when the behavioral level of experience is not addressed in software design. And this example is not even the most extreme: a man in Lafayette, Colorado was arrested on suspicion of felony menacing, reckless endangerment, and the prohibited use of weapons after he shot his laptop four times in a bar and hung it on the on the wall like a hunting trophy. He never explained what prompted his actions, but told police that it seemed like the right thing to do at the time [24]. These are extreme examples of what is referred to as “computer rage” [25]; computer rage is widespread, for example, 70% of computer users surveyed in the UK admitted to shouting, swearing, or being violent to their computers [16]. The cost to British industry is a staggering £25,000 ($40,000) per employee per year in lost productivity as users work to troubleshoot computer problems [25]. As astounding as this estimate is, controlled research backs it up, one study showing that 38% of computer user’s time is lost to frustrating experiences [23]. Chief among these frustrations were user interface issues such as poor error messages, bad URLs, system responses that are inconsistent with user actions, and annoying, missing, or hard to find features.

For companies that use software and intranet information sources—whether externally or internally developed—this sort of frustration carries a huge cost in lost productivity and dampened employee moral. For companies that sell software and Web services, this sort of frustration provokes customer defection, damages hard-won reputations, and reduces word-of-mouth referrals, the consequences of which are well documented: reducing customer defections by 5% can boost profits by 25% to 85% [110] and retaining existing customers is six times less expensive than attracting new ones [114]. Add to this the escalating support cost when users vent to support staff, and you begin to understand the business impact of poor behavioral design.

A positive behavioral experience results from a combination of product usefulness and usability. A product is useful when it meets the day-to-day needs of its users. In other words, most of its features are needed or wanted by most of its users. This is a delicate balancing act: missing features will frustrate users, while too many features will make the product unwieldy and cumbersome. Observational methods outlined in the User Research section  (see p. 15) can help you discover the features that have significant user appeal and avoid investing resources to develop features that will simply clutter your product.

A product is usable when it is effective, efficient, engaging, easy to learn, and error tolerant [106]. These “Five Es” of usability are explained below:

• Effective. Affords goal accomplishment with minimum effort.
• Efficient. Allows rapid task completion with few errors.
• Engaging. Offers enjoyable day-to-day operation.
• Easy to learn. Supports rapid initial skill acquisition and expanded skill development with experience.
• Error tolerant. Prevents errors and supports error recovery.

A product with good usability will have all the above attributes. Combined with usefulness, usability provides a consistently positive behavioral experience that inspires high-levels of product loyalty. Behavioral and visceral appeal together create a product experience that is attractive on first impression and remains enjoyable over the long haul, making a compelling product offering. However, there is one more level of experience to consider during product development, the level.

• Executive Summary
• What Is User Experience Engineering?
• What Are The Levels Of UX?
  • The Visceral Level
  • The Behavioral Level
  • The Sociocultural Level

• How Is User Experience Engineered?
• Who Uses UXE?
• Why Use UXE?
• When To Use UXE?
• User Experience References

We are social animals, and the sociocultural level of our experience influences our product preferences and interaction styles. We need to identify with a social group, and we use that group identification as a method of self-definition [131]. Our product choices are influenced by the preferences of our group [7; 36] and we use product preferences to communicate our group affiliation and self-identity both to others and ourselves. Even those who specifically reject making a fashion statement make the statement (to themselves and perhaps to others) that they are too practical to be influenced by the whims of fashion.

Tapping into group identification may be as basic as the Betty Crocker Company appealing to a “good homemaker” identity, or it can reach extremes. Schouten and McAlexander described the Harley-Davidson brand as “in effect, a religious icon, around which an entire ideology of consumption is articulated” [119, p. 50]. In the words of one owner, “I can tell you that owning a Harley is like being in a brotherhood. Everyone that has one feels a sense of kinship with other Harley owners” [103, p. 21]. Perhaps it is not surprising that 94% of Harley-Davidson owners would buy one again [99]. Harley-Davidson consumer loyalty illustrates that group identity influences are “sticky,” meaning once they are established they are very difficult to change with feature-based analysis or counterfactual reasoning [11].

The applications of group and self-identity principles have been considered by marketing professionals [108]. Additionally, human-computer interaction researchers have shown that when we interact with cognitively complex products like computers, group identity dynamics can make us feel like the computer is part of our team. In one study, participants who interacted with a computer designed to evoke group affiliation responses “perceived the computer to be more similar to themselves, saw themselves as more cooperative, were more open to influence from the computer, thought the information from the computer was of higher quality, found the information from the computer friendlier” [83, p. 669] when compared to participants in the control condition.

Group affiliation is only one social psychological principle that humans demonstrate when interacting with computers [39; 109]. When computers flatter us, we feel better about ourselves and our performance, and we like the computer more [40]. When computers help us, we are willing to help them back, a principle referred to as reciprocity [38]. When a computer listens empathetically, programmed with active listening skills, we feel less frustrated [63]. And when we interact with a computer that is designed to establish and maintain long-term social-emotional relationships, we respect it more, like it more, trust it more, and want to continue interacting with it more than the ordinary model [9]. We do this because our brains have not evolved to deal with cognitively complex technology like computers, so we treat computers like what they resemble most from our evolutionary history, another person. And we do this even if our only interaction is through text, even if we are computer savvy, and even if we do not think we will [109].

In human-human interactions, developing long-term social relationships has many benefits. In helping professions—like counseling and coaching—it is associated with successful outcomes [94]. In education, it predicts students’ cognitive, behavioral, and emotional engagement [123]. In business, it correlates with managerial effectiveness, employee productivity [41], and marketing persuasiveness [102]. Therefore, it is likely that attending to the social aspects of interactive technology will yield similar benefits.

Visceral appeal creates a product experience that is attractive on first impression. Good behavioral experience ensures it remains enjoyable over time. Sociocultural experience reinforces the first two levels: it influences product preferences, adding to any product appeal generated at the visceral level, and it enhances the ongoing product experience by providing a rewarding social dimension.

Now that we have reviewed the nature of user experience, let’s consider how it can be engineered.

• Executive Summary
• What Is User Experience Engineering?
• What Are The Levels Of UX?
  • The Visceral Level
  • The Behavioral Level
  • The Sociocultural Level

• How Is User Experience Engineered?
• Who Uses UXE?
• Why Use UXE?
• When To Use UXE?
• User Experience References