from Diane Nahl’s page at http://www2.hawaii.edu/~nahl/articles/user/user1to13.html#RTFToC2
The term “user-centered” arose in the minds of librarians and information specialists who wanted more services for end-users, patrons, clients, students, and the public at large within the information environment. They saw the status quo as “system-centered,” that is, insufficiently responsive to user needs and realities. One early observer notes the “growing movement” at the time for user-oriented systems to shift from “source-controlled” to “receiver-controlled”(1). The expression user-centered has become, a maxim, a principle, and represents a new paradigm for defining, measuring, and explaining the behavior of library users, database searchers, and Internet navigators. A search of the literature of the past two decades yields dozens of articles and some books bearing in their title or abstract, one of the following expressions of this new orientation:
Two themes emerged in reviewing literature with a conscious user-centered focus: (1) methods of application that seek to alleviate specific user needs, and (2) the integration of theoretical justifications and accounts that researchers have proposed for transforming the information environment through user-centered interventions.
It is worth noting at the outset that the system-centered approach in the design of information facilities routinely advises a testing procedure with actual users within the design process, before features are finalized. However, this technique has proved to be inadequate primarily because user-categories have been based on designers’ intuitions rather than on research about how users actually perceive, think, organize, and intend during the information seeking process. As pointed out by Walther and O’Neil in the early days of online users, “Intuition and good judgment on the part of the designer seem insufficient for specifying the features which an interface should possess” (p. 115). Despite this attempt to give users a greater weight in the interface design equation, system-centeredness has remained essentially the same. The reason for this is clarified in the discussion of the advent of the user-centered paradigm and its essential characteristics. In speaking of this basic shift, one commentator points to a distinction between the concept of information as “like a brick” while users are like “empty buckets into which [information] bricks can be thrown” (3)(p. 160). According to Dervin, the invalidity of this metaphor is shown by two outcomes: the “nonuse of information” by both professionals and the general public, and the user-oriented case studies of how people acquire and assimilate information in their daily lives and occupations.
Reviewing the data, Dervin concludes:
The important point here is, when it comes to understanding how and why and with what effect human beings pay attention to, process, and use something that an outside observer calls information, we must start by understanding what the user (or potential user) calls information. Information processing and use are, within the context of relativistic assumptions about information, sense-making activities. The emphasis here is on the word “making” for it denotes that the perceiver of the information is not an empty bucket but is actively making sense” (p. 164-5).
Information as an “observer construct” has had to give way to information as a “user construct” since the “empty bucket has evolved into a thinking, self-controlling human being” and “information changes from brick to clay, moved and shaped in unique ways by each perceiver” (3)(p. 169). Since making sense of the world is part of the human condition, knowledge-building is therefore a “personal information seeking” activity:
Questions asked have dealt with locating self and others (Where am I? Where are they?), with finding possibilities (What can I do?) and evaluating possibilities (Will it work?), and with assessing aloneness (Is anyone listening? Doesn’t anyone else agree? Am I the only one?). Perhaps the most important aspect of the findings to date is that they support the premise that looking for information relativistically is a more powerful entry for understanding information needs and use” (3)(p. 170).
Looking at information seeking relatively requires one to recognize that situation-specific factors are more important to users than general considerations. For example, users’ interests and involvement (“issue oriented”) are better predictors of information-seeking activity than users’ education or experience. When individuals see their situation as giving them options for decision or movement, they are more likely to engage in information seeking than when they see themselves under total constraint (3)(p. 171-2). Another reason that information is “relativistic” is that “the effect of the information received is the use created for it by the user.” In other words, the situation-specific, momentary information need determines what information will have impact at that time. Research in this new “relativistic information framework” can help systems designers make the shift to this user-centered orientation.
In the early days of the new paradigm there was not yet a full appreciation of the need to remove the centrality of the system. User-centered consciousness was not fully awakened until one saw the necessity of designing systems through understanding users. The following is an example of an early attempt to promote “an empirical approach to user-centered design:”
The problems which accrue to the human user by virtue of being made a component of the system — of the user actually being placed on-line to the computer — were largely ignored until very recently. A user protest led to calls for a shift of emphasis from the elegance of algorithms and computational efficiency to the discovery of ways to make the on-line user interface more acceptable to the user. (2)(p.114).
As it turned out, more than “a shift of emphasis” was required. For instance, Walther and O’Neil define the flexibility of an interface as “the factors inherent in the interface program which would make it easier or more convenient for the user to express his commands, given that the commands had to follow a specific syntax” (2)(p.116). However, this orientation remains part of the system-centered paradigm since it passively accepts the priority or fixity of the system, though it recognizes that acceptability and convenience to users is to be taken into account. Another example is in the earlier attempts to use empirical or objective measures of user satisfaction. Researchers often turned to existing “attitude measures” such as the semantic differential (4) which provides subjects with a series of bi-polar scales upon which to rate their attitude toward aspects of the system:
The results indicate that the users of the flexible version [of the online editor], irrespective of any other factors, rated their version as more tolerant, more flexible, more like a person, more friendly, and more pleasant than the inflexible version” (2)(p.117).
Future development of the user-centered paradigm will view such attempts as insufficient. Attitude scales have three inherent weaknesses relating to the object being rated, the timing of the rating, and its content. These problems need to be remedied by utilizing different techniques that avoid them.
First, the object to be rated by the user needs to be the user’s experience, not the system. Thus, not, “On a scale of 1 to 7, how easy is this editor to use?” but rather, “On a scale of 1 to 7, how much confusion did you experience with this editor?” Second, the act of rating needs to be in close proximity to where the activity occurs, not at the end of a session, or even later, but concurrently, during the activity itself. Thus, more than a single probe is necessary, since a user’s experience may vary greatly from one minute to the next, depending on various difficulties. Third, the content of the rating category must originate from the user’s mental structure rather than the experimenter’s. Otherwise, measures such as attitude scales, survey questions, census data, and personality tests represent system-centered accommodations to user protests of user-unfriendly systems.
More recent statements of user-centered system evaluation and design continue to promote the centrality of users (5) but there is a shift in emphasis away from treating users as a method of determining baseline measures for design standards, toward “application-based evaluation procedures.” This represents an orientation toward operational effectiveness rather than design efficiency. In this view, system redesign can be motivated by how inconvenient it is to learn rather than how effectively it can perform under ideal conditions.
Wallace has proposed a framework for evaluating the user-friendliness of a system (6). The list includes the following types of measures:
* users must be given options for preferences
* online system operation and assistance should be available at beginner and more advanced levels
* system behavior has to be transparent to users
* warning messages must be benign or light-hearted
* system design must take into account the physical and psychological needs of users
* system use should require no special skills
* the general language of novices and their routine level of communicative skills should not be surpassed in instructions or explanations
* the system should behave in a uniform way to allow users to anticipate functions
* a variety of types of problem-solving should be available for particular operations
* learning by doing should be the preferred mode of instruction and presentation
One project that implemented these and additional user-friendly features is known as ELSA, “An Intelligent Electronic Library Search Assistant” (7). Four design concepts guided the development of ELSA:
* using labels that are transparent to users (e.g., buttons with the names “Run Search,” “New Search,” and “Show Full List”
* providing assistance with controlled vocabulary (e.g., a synonyms list)
* actively helping users explore topic areas (e.g., providing suggestions for narrower topics and screening out more distantly related items)
* accommodating different styles of interaction (e.g., an option to type in search items or select them with the mouse from a list)
Another historical example is the user-centered redesign of the MELVYL system in response to empirically discovering the answer to the question, “What do users really want?” According to Farley (8), the process of collecting and maintaining a comment database optional to users, has uncovered bugs in the system as well as numerous user-unfriendly features that could form the basis for redesign. Today, with Internet networking of libraries, MELVYL has learned to “compete in attractiveness” to users who are more sophisticated and computer literate, though still novice searchers.
The development of intelligent search assistants such as ELSA would not have occurred without the climate created by the user-centered revolution that gave it scientific legitimacy and made research grants available for user studies. The first phase of the transformation concluded when user-friendliness became a legitimate scientific research issue. An important thrust came from the human-computer interaction field populated by engineers, programmers, and applied psychologists.
Toward Human-Centered Design
In a whimsical mood, one of the architects of the user-centered revolution in the area of systems design and technology, describes a still common attitude regarding the introduction of new technology:
One of the things that stands out when talking to long-term users of poorly designed systems is that these people take great pride in their skills. They had to go through great difficulties to master the system, and they are rightfully proud of having done so. … Rather than ease the situation for those who follow, it becomes a sort of initiation rite. The hardy survivors of the experience claim to share a common bond and look with disdain upon those who have not been through the same rites. They share horror stories with one another” (9) p.176.
Norman reveals that he “got attacked by hundreds of professional programmers across the country” when he wrote an article criticizing the UNIX system as user-unfriendly: “If I didn’t approve of UNIX, they told me, I had no business using it. Besides, who was I anyway to criticize computer software? In other words, you weren’t allowed to criticize unless you were a professional. Being a mere user of the stuff didn’t qualify” (9)(p.177). However, a new paradigm was in the ascendancy, and is achieving full victory. The user-centered revolution not only gives users more clout in the design equation but works to make users the central point of focus and interest for planners, backers, designers, engineers, and trainers of information systems.
Understandability and usability are two principles that apply equally to design and documentation issues. According to proponents of “cognitive engineering,” (10) understandibility of instructions depends on providing a good conceptual model of the task or system. Good models are those that allow users to predict the effects of their actions. Users will invent false models when the appearance of some system features (the visible setup) does not match the functions desired (10)(p.16). The designer’s model is formalized by the design process itself. The user’s model evolves through interaction with the system. The system image consists of the visible structure or appearance of the interface (controls, keys, instructions, labels, visualization aids or interface metaphor, etc.). All communication between designer and user takes place through the system image. If the system image does not make the design model clear, users end up with a wrong mental model as evidenced by symptoms such as inability to predict, difficulty in using, having a shallow understanding, and inability to solve problems. One of the key factors in helping users develop an accurate conceptual model is to provide immediate feedback for every action or choice made.