Introduction
User-Centered Design(UCD) is a design process in which the needs, wants and limitations of end users of a system’s interface are given primary attention at every stage of the design process. It is a multi-stage problem solving process that requires the analysis of user interface as well as the validity of the assumptions with the behavior of actual users. In UCD, the main focus is on the user’s satisfaction. For implementing the ideas of UCD, we have to go through some standard processes. UCD is widely used in different areas where the direct interaction of users take place. We will also discuss on the contextual design and inquiry. Contextual design(CD) adds some sensing and responding aspects on demand besides some conventionally used I/O devices such as screens, keyboards and mice. Contextual Inquiry(CI) is for the explicit purpose of supporting engineering efforts. CI uses a well-defined set of procedures which includes conversations and interviewing the users about their works in the real environments and thus differs from the traditional experimental techniques.
UCD as an approach of Interaction Design (IxD)
Interaction design is the art of facilitating or instigating interactions between humans (or their agents), mediated by products. Interactions mean communication, either one-on-one (a telephone call), one-to-many (blogs), or many-to-many (the stock market). The products an interaction designer creates can be digital or analogue, physical or incorporeal or some combination thereof. Interaction design is concerned with the behavior of products, with how products work. A lot of an interaction designer’s time will be spent defining these behaviors, but the designer should never forget that the goal is to facilitate interactions between humans.
There are many approaches to interaction design (IxD). UCD is one of them. UCD is an approach to creating products that considers the needs and goals of the user to be the highest priority. As the user gets most priority in UCD and it’s also the main focus of IxD, the UCD can be described as an approach of IxD.
User-Centered Design(UCD) Process
UCD is a designing process where the end-users are in the center of consideration. It consults users during requirements gathering and usability testing about their needs to design a successful process.
Design Principles
Some design principles are needed to guide the design. Norman(1988) suggested that the following seven principles of design are essential for facilitating the designer’s task:
- Use both knowledge in the world and knowledge in the head. By building conceptual models, write manuals that are easily understood and that are written before the design is implemented.
- Simplify the structure of tasks. Make sure not to overload the short-term memory, or the long term memory of the user. On average the user is able to remember five things at a time. Make sure the task in consistent and provide mental aids for easy retrieval of information from long-term memory. Make sure the user has control over the task.
- Make things visible: bridge the gulfs of Execution and Evaluation. The user should be able to figure out the use of an object by seeing the right buttons or devices for executing an operation.
- Get the mappings right. One way to make things understandable is to use graphics.
- Exploit the power of constraints, both natural and artificial, in order to give the user the feel that there is one thing to do.
- Design for error. Plan for any possible error that can be made, this way the user will be allowed the option of recovery from any possible error made.
- When all else fails, standardize. Create an international standard if something cannot be designed without arbitrary mappings.
Conceptual design and physical design issues in UCD
There are established processes for interaction design in the context of a User-Centered Design (UCD) methodology. Designers must balance a variety of considerations, including the needs and goals of the users, the constraints imposed by the context of use, and the challenges that arise naturally from the interaction between humans and machines; to come up with solutions. Commonly used design methods include paper prototyping and cognitive walkthroughs. The design process is iterative, meaning that proposed solutions are refined through repeated cycles of prototype evaluation.
Design can occur on several different levels:
- Conceptual design is a basic foundation that defines the structure of the solution, including the functional elements of the product, their relationships and the system behavior. Conceptual design is the vital stage of the product creation that defines the success or failure of the product usability.
- Physical design is a more refined level that defines the aesthetics of the solution. This includes, for example language (and, to some extent, content) and branding. In contrast with conceptual design, physical design defines the success or failure of the product appeal.
UCD Models
The major characteristics of UCD are the active participation of real users, as well as an iteration of design solutions.
- Cooperative design: It involves designers and users on an equal footing. This is the Scandinavian tradition of design of IT artifacts and it has been evolving since 1970.
- Participatory design (PD): A North American term for the same concept, inspired by Cooperative Design, focusing on the participation of users. Since 1990, there has been a bi-annual Participatory Design Conference.
- Contextual design: “User-Centered Design” in the actual context, including some ideas from Participatory design.
How to Involve Users in Design?
It is necessary to think carefully about who is a user and how to involve users in the design process. Obviously users are the people who will use the final product or artifact to accomplish a task or goal. Besides, the people who manage the users have needs and expectations too. The persons who are affected in some way by the use of the artifact or use the products and services of the artifact are also considered to be the users as well.
Eason (1987) identified three types of users:
- Primary Users: Primary users are those persons who actually use the artifact.
- Secondary Users: Secondary users are those who will occasionally use the artifact or those who use it through an intermediary.
- Tertiary Users: Tertiary users are persons who will be affected by the use of the artifact or make decisions about its purchase.
The successful design of a product must take into account the wide range of stakeholders of the artifact. Not everyone who is a stakeholder needs to be represented on a design team, but the effect of the artifact on them must be considered.
When users have been identified and a thorough investigation of the needs of that specific users have been conducted by performing task and needs analysis, designers can develop alternative design solutions to be evaluated by the users. It can be a simple pen and paper work such as drawings in the beginning. Then, a feedback is taken from the users that helps the designers to understand the intended purpose(s) of the artifact and provide information which does not come out of the initial interviews, observations, and needs analysis. As the design cycle progresses, prototypes can be produced and user tested. At this point, designers should pay close attention to the evaluations by the users as they will help identify measurable usability criteria such as effectiveness, efficiency, safety, utility, learn-ability and memorability. At each and every step, feedback is an essential thing that can help designers to plan and design the system as well as helpful to the users to be self-satisfied.
Evaluation techniques
- Design walkthroughs (“cognitive walkthroughs”)
The cognitive walkthrough method is a usability inspection method used to identify usability issues in a piece of software or web site, focusing on how easy it is for new users to accomplish tasks with the system. The method is rooted in the notion that users typically prefer to learn a system by using it to accomplish tasks, rather than, for example, studying a manual. The method is prized for its ability to generate results quickly with low cost, especially when compared to usability testing, as well as the ability to apply the method early in the design phases, before coding has even begun.
After the task analysis has been made the participants perform the walkthrough by asking themselves a set of questions for each sub-task. Typically four questions are asked:
- Will the user try to achieve the effect that the sub-task has? Does the user understand that this sub-task is needed to reach the user’s goal?
- Will the user notice that the correct action is available? E.g. is the button visible?
- Will the user understand that the wanted sub-task can be achieved by the action? E.g. the right button is visible but the user does not understand the text and will therefore not click on it.
- Does the user get feedback? Will the user know that they have done the right thing after performing the action?
By answering the questions for each sub-task usability problems will be noticed.
A heuristic evaluation is a discount usability inspection method for computer software that helps to identify usability problems in the user interface (UI) design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles (the “heuristics”). These evaluation methods are now widely taught and practiced in the New Media sector, where UIs are often designed in a short space of time on a budget that may restrict the amount of money available to provide for other types of interface testing.
The main goal of heuristic evaluations is to identify any problems associated with the design of user interfaces. Heuristic evaluations are one of the most informal methods of usability inspection in the field of human-computer interaction. There are many sets of usability design heuristics; they are not mutually exclusive and cover many of the same aspects of interface design. Heuristic evaluation requires only one expert, reducing the complexity and expended time for evaluation. Most heuristic evaluations can be accomplished in a matter of days. The time required varies with the size of the artifact, its complexity, the purpose of the review, the nature of the usability issues that arise in the review, and the competence of the reviewers.
Usability testing is a technique used to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system. This is in contrast with usability inspection methods where experts use different methods to evaluate a user interface without involving users. Usability testing focuses on measuring a human-made product’s capacity to meet its intended purpose. Examples of products that commonly benefit from usability testing are foods, consumer products, web sites or web applications, computer interfaces, documents, and devices. Usability testing measures the usability, or ease of use, of a specific object or set of objects, whereas general human-computer interaction studies attempt to formulate universal principles.
Setting up a usability test involves carefully creating a scenario, or realistic situation, wherein the person performs a list of tasks using the product being tested while observers watch and take notes. Several other test instruments such as scripted instructions, paper prototypes, and pre- and post-test questionnaires are also used to gather feedback on the product being tested. For example, to test the attachment function of an e-mail program, a scenario would describe a situation where a person needs to send an e-mail attachment, and ask him or her to undertake this task. The aim is to observe how people function in a realistic manner, so that developers can see problem areas, and what people like. Techniques popularly used to gather data during a usability test include think aloud protocol and eye trackingUsability testing focuses on user needs, uses empirical measurement, and iterative design. According to Dumas and Redish (1993), it aims to achieve the following five goals:
- Improve the product’s usability.
- Involve real users in the testing.
- Give the users real tasks to accomplish.
- Enable testers to observe and record the actions of the participants.
- Enable testers analyze the data obtained and make changes accordingly.
Use of Persona and scenarios in IxD or UCD:
Persona provides an illustration of a virtual user. There are more information that you can extract from a persona such as user’s profile, goal, task to be completed, how he/she use the application tool, their daily life, behavior, common practice, user expectation, etc. All these information are good inputs for brainstorming and developing a new product. Personas are tools for UCD. Personas are based on research and synthesized from data – not creative fiction. Personas are user archetypes based on a synthesis of goals, behaviors and motivations. Personas may include personal details such as names, photographs and demographics, but they do not in any way define personas. Indeed in many cases you will find personas lack precisely this kind of information because they’re not directly relevant.
Scenarios describe the greater context of a task including the conditions, motivation, and environment of the task for a particular user group. These usually include all the details interaction designers need to understand what the user is trying to do and what they need.
There are many varieties of scenarios. Here are some of the types of scenarios that are described in the literature. They vary in several dimensions including level of detail, focus on person versus technology or organization; descriptions of present versus future.
- Alternative world scenario
- Organizational Scenarios
- Individual task-level scenarios
- Making-sense scenarios
- Technology scenarios
- Concept of operation
- Misuse scenarios
- Day-in-the-life scenarios
- Normal case scenarios
- Alternative case scenarios
- Exception scenarios
- What-if scenarios
- Brief scenarios
- Vignettes
- Elaborated scenarios
Applications Areas
User-centered design has been used with marked success on a wide variety of applications in different systems.
- Software – Every kind of software has the application of UCD.
- Hardware – UCD is also needed in some applications of hardware’s.
- Web-based applications – UCD is largely used in web based areas like payroll, finance, insurance, and banking applications.
- E-commerce – Applications of UCD are largely used in the sector of E-Commerce.
- Distance education and classroom instruction on the Internet.
- Geographical information systems – UCD is also used in the area of GIS.
- Medical instrumentation – UCD is used in different sectors of medical science.
- Consumer electronics products.
- Industrial automation.
Contexual Design
Contextual Design (CD) is a user-centered design process developed by Hugh Beyer and Karen Holtzblatt. It incorporates ethnographic (comparative study of people) methods for gathering data relevant to the product, field studies, rationalizing workflows, system and designing human-computer interfaces. In practice, this means that researchers aggregate data from users into a final product.
Definition of Context
The way humans interact with one another is much more successful than a human interacts with a computer because of the richness of the language they share, the common understanding of how the world works, and an implicit understanding of each other. Humans can use implicit situational information, or “context” to increase the bandwidth of the conversation.
So, by improving the computer’s access to context, it will be possible to introduce a better interaction in HCI.
Schilit and Theimer refer to context as location, identities of nearby people and objects, and changes to those objects. Context may be defined as an environment or situation. Schilit et al. claim that the important aspects of context are: where you are, who you are with, and what resources are nearby. Context is any information that can be used to characterize the
situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves.
Contextual design process consists of the following top-level steps:
Contextual inquiry/Collecting Data: Contextual inquiry is a user-centered design (UCD) method, part of the contextual design methodology, that happens in the product development lifecycle. The daily routines or processes of the users are observed and discovered so that a product or website or interface can be best designed to be worked with. It comprises preparation, evaluation, analysis, and design phases.
Contextual inquiry involves collecting detailed information about customer behavior and expectations by observing and interviewing them. The researcher should stay in the background and let the user to be in the main role as much as possible. In this case, a researcher is learning as an apprentice and the customer is the master of work which helps the researchers to better understand the customer’s work.
Contexual inquiry requires some procedures that may be summarized as follows:
- Interview users about their work.
- Concrete discussion about what the user is doing.
- Let the user lead the conversation.
- Sharing of the assumptions with the users.
- Summarize the understanding at the end of each session to find out who to talk to next and what to focus on next.
- Building of an understanding of the user work and ideas.
- Build a first cut of a User Environment based on the understanding.
Work modeling: Detailed work models are created in order to understand the workflow. Contextual design consists of five work models which are used to model the work tasks and details of the working environment. The models are:
- Flow model: represents the coordination, interaction and responsibilities of the people in a certain work practice.
- Sequence model: represents the required steps to accomplish a certain activity.
- Cultural model: represents the norms, influences, and pressures that are present in the work environment.
- Artifact model: represents the documents or other products that are created while working. Artifacts often have a structure or styling that could represent the user’s way of structuring the work.
- Physical model: represents the physical environment where the work tasks are accomplished; often, there are multiple physical models representing, e.g., office layout, network topology, or the layout of tools on a computer display.
Consolidation:Data from individual customer interviews are analyzed and combined together in order to reveal the common patterns. It can be accomplished through the following steps:
- A single observation is written on each piece of paper.
- Individual notes are grouped according the similarity of their contents.
- These groups are labeled with distinct colors which represent distinct levels in the hierarchy.
- hen the groups are combined with other groups to get the final result of observations in a hierarchy.
Here, a bottom-up approached “Affinity Diagram” is used to include the ideas and relevant issues of the process.
Work redesign:Work redesign uses the consolidated data to drive conversations about how to improve work by providing a system that better supports the new work practice. The redesigned work practice is captured by a vision in the storyboards and sketches capturing scenarios of how people will work with the new system. The complete workflow helps the design team address the problems and design the new workflow.
The User Environment Design: The User Environment Design captures the floor plan of the new system. It shows each part of the system, how it supports the user’s work, exactly what function is available in that part, and how the user gets to and from other parts of the system. User Environment Design (UED) diagram, which displays the focus areas, i.e., areas which are visible to the user or which are relevant to the user.
Prototyping and Implementation: Testing the design ideas with paper prototypes or even with more sophisticated demos before the implementation phase helps the designers to get feedback from the customers about the new system and develop the design further. Depending on the results of the prototype test, more iterations or alternative designs may be needed for the implementation purpose.
Application areas of Contextual Design
Contextual design has primarily been used for the design of computer information systems, including hardware and software. It has also been applied to the design of the digital libraries and other learning technologies. Contextual design has also been used as a means of learning and teaching UCD.
References
1. User-Centered Design – Chadia Abras, Diane Maloney-Krichmar, Jenny Preece.
2. Identifying and Selecting Users for User-Centered Design Sari Kujala and Marjo Kauppinen .
3. User Modeling in Human – Computer Interaction Gerhard Fischer.
4. Design At Work – Cooperative design of Computer Systems, Lawrence Erlbaum 1991.
5. Contextual Design, Kaufmann 1998.
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