Usability Techniques

This section describes standardized usability techniques. Using these repeatable techniques, high-quality system usability can be achieved. The techniques have been created based upon a model that can be tailored. The information in this section will help either the development project manager (in small projects) or the usability engineer in the selection of the appropriate methods and techniques from the resources suitable for the project.

Because they are standardized procedures, usability techniques provide results that can be compared. Results from a usability activity can be compared with existing results from previous projects, as well as with results from other organizations and companies if these parties agree to exchange such information. The following subsections contain brief summaries of key usability techniques separated into stages.

Requirements Stage

  1. Project Initiation: In this stage, the project objectives have been defined. The key project leads are engaged in the various project-related planning activities. Since usability is still not tightly integrated into the overall system development processes, it may need to be sold to the project sponsors. The key usability techniques used at this stage are the following:

    • Usability Planning: Planning is essential for the success of any process. Usability planning requires identifying all the usability techniques to be applied during the project life cycle, identifying dependencies with other processes, and allocating the resources necessary for success.

    • Cost-benefit Analysis: This technique involves working with the key stakeholders and analyzing the costs and benefits of the usability activities.

  2. Gathering and Analyzing Requirements: In this stage, various usability techniques are applied to users, stakeholders, existing product versions, similar products, and competitor products to gather information that can be used for identifying the usability criterion and the functional requirements. Usability techniques may leverage marketing data, but they differ from marketing techniques in their unique focus on the user and stakeholder needs rather than marketing needs.

    • Group Discussion/Future Workshops: Group discussions are based on stakeholders within the design process discussing new ideas, design options, costs and benefits, screen layouts, and so on, when relevant to the design process. The future workshops concept is designed specifically to allow participants to step forward though they are not used to having a voice in the discussion process.

    • Usability Context Analysis: Usability context analysis (UCA) is a structured method for eliciting detailed information about a product and how it will be used, as well as for deriving a plan for a user-based evaluation of a product. For this method, stakeholders meet to detail the actual circumstances (or intended use) of a product. The objective of the method is to collect information this should be done preferably through a well-prepared meeting, but it may also be done through a series of personal interviews (for example, if schedules in a busy company do not permit essential personnel to attend a general meeting).

    • Naturalistic Observation: Observational methods involve an investigator viewing users as they work and taking notes on the activities taking place. Observation may be either direct, where the investigator is actually present during the task, or indirect, where the task is viewed by some other means, such as a video camera.

    • Surveys: A survey involves administering standard questionnaires to a large sample population. Surveys can help determine customer preferences, work practices, and attitudes. The two types of surveys are (1) closed, in which respondents are asked to select from available responses and (2) open, in which respondents are free to answer as they wish.

    • Ethnographic Approach/Contextual Inquiry: The ethnographic approach emphasizes the understanding of behavior in context through the participation of the investigator in the situation being studied as an active member of the team of users involved in the situation. The ethnographic approach is essentially the traditional systems analysis approach enriched by contact with sociology and social anthropology. A close variant, contextual inquiry, has been adopted by Digital.

    • Diary Methods: Diary methods require the informants to record activities they are engaged in throughout a normal day. The structure of diaries varies from unstructured or open-ended, in which the informant writes in his or her own words, to highly structured tick-box questionnaires.

    • Focus Groups: A focus group brings together a cross section of stakeholders in an informal discussion group format. Views on relevant topics are elicited by a facilitator. Meetings can be audio or video taped for later analysis.

    • Interviews: Interviewing is a common technique in which domain experts are asked questions by an interviewer for the purpose of obtaining domain knowledge. Interviewing is not as simple as it may appear. The three types of interviews are unstructured, semistructured, and structured. The type, detail, and validity of data gathered vary with the type of interview and the experience of the interviewer.

  3. Usability Design Criterion: In this stage, the actual benchmarks and the usability criterions that become the design objectives are formulated. These criterions also serve as the usability test objectives. Each criterion is measured on the three attributes of efficiency, effectiveness, and satisfaction. Some criteria include, but are not limited to, learnability, helpfulness, meeting needs of trained users, meeting needs to walk up and use, meeting needs for infrequent or intermittent use, minimization of support requirements, error tolerance, legibility, and more.

  4. Design, Prototype, and Evaluate Requirements: In this stage, the requirements and user needs are synthesized into multiple design options. Each design option focuses on emphasizing a different user need. Different usability techniques are then applied to synthesize the requirements. Some usability techniques help with the design and prototyping of the solution and some that assist in soliciting meaningful user feedback during the usability testing and evaluation sessions.

    • Functionality Matrix: This is a way of specifying which functions each user type needs. Identifying which tasks are critical allows more time for essential functions during design and usability testing. This technique is applicable to situations with tasks that are well defined.

    • Task Allocation Charts: A range of task allocation options is established between users and the computer system to identify the optimal division of labor needed to provide satisfying jobs and efficient operation of the entire work process. Task allocation charts are most useful for systems that affect whole work processes rather than single users or single-task products.

    • Task Analysis: Task analysis can be defined as the study of what a user is required to do, in terms of actions and/or cognitive processes, to achieve a system goal. Task analysis is, therefore, a methodology that is supported by a number of techniques to help the analyst collect information, organize it, and use it to make various judgments or design decisions.

    • Wizard of Oz Prototyping: This approach involves a user interacting with a computer system that is actually operated by a hidden developer, referred to as the wizard. The wizard processes input from a user and simulates system output. During this process, the users are led to believe they are interacting directly with the system. This form of prototyping is popular for testing voice response systems and artificial intelligence systems.

    • Paper Prototyping: This method features the use of simple materials and equipment to create a paper-based simulation of an interface or system. Paper prototypes provide a valuable and cost-effective means of evaluating and iterating design options before a team gets committed to one implementation. Interface elements, such as menus, windows, dialogues, and icons, may be sketched on paper or created in advance using cards, acetate, pens, and so on. The result is sometimes referred to as a low-fidelity prototype. When the paper prototype has been prepared, a member of the design team sits before a user and moves interface elements around in response to the user's actions. A facilitator facilitates the session by providing task instructions and encouraging users to express their thoughts and impressions.

    • Scenario Building: Scenarios are characterizations of users and their tasks in a specified context. They offer concrete representations of users working with a computer system to achieve a particular goal. The primary objective of scenario building is to generate usability requirements or targets. Scenarios also offer the opportunity to explore the implications of design options and to communicate interface issues to colleagues for comment and critical feedback. A variation of this technique has been adopted by the agile framework as user stories.

    • Storyboarding/Presentation Scenarios: Storyboards are sequences of images that demonstrate the relationships among individual screens and actions within a system. A typical storyboard will contain a number of images depicting features such as menus, dialogue boxes, and windows. The sequencing of these screen representations conveys further information regarding the structure, functionality, and navigation options available within an intended system.

    • Empathic Modeling: This method has so far been mainly developed for use with disabled users. With empathic modeling, designers/developers strive to put themselves in the position of a disabled user. This is done by simulating the disability through various techniques. Similar methods are widely used in many application areas, but they are rarely referred to as empathic modeling. This is a general method that could be applied to a broad range of applications.

    • Rapid Prototyping (software or hardware based): This method is concerned with developing different proposed concepts through software or hardware prototypes and evaluating them. In general, the process is termed rapid prototyping. The development of a simulation or prototype of the future system can be very helpful, allowing users to visualize the system and to provide feedback on it. Thus it can be used to clarify user requirements options.

Design, Development, and Testing Stage

  1. Creating the functional (and nonfunctional) specifications: In this process stage, the prototype from the previous stage is used for documenting functionality with notes for the development team. This helps clarify for everyone engaged in the development and testing of the application what needs to be built and the intention for building it.

  2. Develop Solution: This is a largely a development-intensive stage in which code is written. Usability parishioners are involved with the development team in deciding low-level design decisions and analyzing development trade-offs.

    • RAD (Rapid Application Development) Workshops: Workshops are set up in which eight to twenty individuals make decisions through the consensus-building leadership of a trained, unbiased facilitator who is not a stakeholder in the future system. A number of different formats for the method are offered. One variation produces formal outputs such as entity-relationship models, which can be input directly into the system specification.

    • JAD (Joint Application Design) Workshops: These workshops are specific variations developed within IBM. Here, users and information systems professionals are drawn together to design a system jointly in a facilitated group session. Six roles are defined, including session leader, user representative, specialist, analyst, information systems representative, and executive sponsor. A 20 percent to 60 percent increase in productivity over traditional design methods is claimed.

    • Laboratory-Based Observation: This approach to studying user behavior in the laboratory may be used at practically any stage in the development process with a representation of the software with which users may interact. The Handbook on Usability Testing by Rubin, 1994, is cited because of its clarity of exposition, but this approach is documented in many sources.

    • Co-operative Evaluation: This is a cost-effective technique for identifying usability problems in prototype products and processes. The technique encourages design teams and users to collaborate on identification of usability issues and their solutions. Users work with a prototype as they carry out tasks set by the design team. During this procedure, users explain what they are doing by talking or thinking aloud. An observer records unexpected user behavior and the user's comments regarding the system. The observer also actively questions the user with respect to their intentions and expectations. This provides qualitative information concerning any difficulties that the users experience and the features or interface elements that give rise to these problems.

    • Parallel Design: It is often helpful to develop possible system concepts with a parallel process in which several different designers work out possible designs. The aim is to develop and evaluate different system ideas before settling on a single approach as a basis for the system. In parallel design, it is important to have the designers working independently, since the goal is to generate as much diversity as possible. Therefore, the designers should not discuss their designs with each other until after they have produced their draft design concepts. When designers have completed their designs, it is likely they will have approached the problem in radically different ways that will give rise to different user systems. It is then possible to combine designs, taking the best features from each. It is important to employ parallel design for novel systems without established guidelines for how the system should operate best.

    • Walk-through: A walk-through is a process of going step by step through a system design to obtain reactions from relevant staff, typically users or experts role-playing users' parts. Typically, one or two members of the design team will guide the walk-through, while one or more users will comment as the walk-through proceeds.

Deployment and Ongoing Refinements

  1. Rollout: At this stage, the product has been tested and is ready for users to use. Very little usability is involved in this stage, other than using this opportunity for gathering requirements for future development activity. Most of the requirements stage techniques that involve observation of the users are applicable at this stage.

  2. Usage Metrics: At this stage, both nonobtrusive and obtrusive methods are used to gather and analyze the actual usage of the system. Analyzing server log files, logging user clicks, and analyzing quality of data are some nonobtrusive techniques, while user surveys, interviews, and other subjective inquiries are obtrusive techniques.



Practical Guide to Enterprise Architecture, A
A Practical Guide to Enterprise Architecture
ISBN: 0131412752
EAN: 2147483647
Year: 2005
Pages: 148

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