Determining Basic Business Functions

Determining Basic Business Functions

A detailed description of what the product will do is prepared. Major system functions are listed and described, including critical system inputs and outputs. A flowchart of major functions is developed. The process the developer will use is summarized as follows:

·        Gain a complete understanding of the user’s mental model based upon:

o   The user’s needs and the user’s profile.

o   A user task analysis.

·        Develop a conceptual model of the system based upon the user’s mental model.

This includes:

o   Defining objects.

o   Developing metaphors.

Understanding the User’s Mental Model

A goal of task analysis, and a goal of understanding the user, is to gain a picture of the user’s mental model. A mental model is an internal representation of a person’s current conceptualization and understanding of something.

Mental models are gradually developed in order to understand, explain, and do something. Mental models enable a person to predict the actions necessary to do things if the actions have been forgotten or have not yet been encountered.

Performing a Task Analysis

User activities are precisely described in a task analysis. Task analysis involves breaking down the user’s activities to the individual task level. The goal is to obtain an understanding of why and how people currently do the things that will be automated.

Knowing why establishes the major work goals; knowing how provides details of actions performed to accomplish these goals. Task analysis also provides information concerning workflows, the interrelationships between people, objects, and actions, and the user’s conceptual frameworks. The output of a task analysis is a complete description of all user tasks and interactions.

One result of a task analysis is a listing of the user’s current tasks. This list should be well documented and maintained. Changes in task requirements can then be easily incorporated as design iteration occurs. Another result is a list of objects the users see as important to what they do. The objects can be sorted into the following categories:

·        Concrete objects—things that can be touched.

·        People who are the object of sentences—normally organization employees, customers,

·        for example.

·        Forms or journals—things that keep track of information.

·        People who are the subject of sentences—normally the users of a system. o Abstract objects—anything not included above.

Developing Conceptual Models

The output of the task analysis is the creation, by the designer, of a conceptual model for the user interface. A conceptual model is the general conceptual framework through which the system’s functions are presented. Such a model describes how the interface will present objects, the relationships between objects, the properties of objects, and the actions that will be performed.

The goal of the designer is to facilitate for the user the development of useful mental model of the system. This is accomplished by presenting to the user a meaningful conceptual model of the system. When the user then encounters the system, his or her existing mental model will, hopefully, mesh well with the system’s conceptual model.

Guidelines for Designing Conceptual Models

Reflect the user’s mental model not the designer’s: A user will have different expectations and levels of knowledge than the designer. So, the mental models of the user and designer will be different. The user is concerned with the task to be performed, the business objectives that must be fulfilled.

Draw physical analogies or present metaphors: Replicate what is familiar and well known. Duplicate actions that are already well learned. A metaphor, to be effective, must be widely applicable within an interface.

Comply with expectancies, habits, routines, and stereotypes: Use familiar associations, avoiding the new and unfamiliar. With color, for example, accepted meanings for red, yellow, and green are already well established. Use words and symbols in their customary ways.

Provide action-response compatibility: All system responses should be compatible with the actions that elicit them. Names of commands, for example, should reflect the actions that will occur.

Make invisible parts and process of a system visible: New users of a system often make erroneous or incomplete assumptions about what is invisible and develop a faulty mental model. As more experience is gained, their mental models evolve to become more accurate and complete. Making invisible parts of a system visible will speed up the process of developing correct mental models.

Provide proper and correct feedback: Be generous in providing feedback. Keep a person informed of what is happening, and what has happened, at all times, including:

Provide visible results of actions. o Display actions in progress.

Provide a continuous indication of status.

Present as much context information as possible.

Provide clear, constructive, and correct error messages.

Avoid anything unnecessary or irrelevant: Never display irrelevant information on the screen. People may try to interpret it and integrate it into their mental models, thereby creating a false one.

Provide design consistency: Design consistency reduces the number of concepts to be learned. Inconsistency requires the mastery of multiple models. If an occasional inconsistency cannot be avoided, explain it to the user.

Provide documentation and a help system that will reinforce the conceptual model: Do not rely on the people to uncover consistencies and metaphors themselves. The help system should offer advice aimed at improving mental models.

Promote the development of both novice and expert mental models : Novices and experts are likely to bring to bear different mental models when using a system.

Defining Objects

Determine all objects that have to be manipulated to get work done. Describe:

o   The objects used in tasks.

o   Object behavior and characteristics that differentiate each kind of object.

o   The relationship of objects to each other and the people using them.

o   The actions performed.

o   The objects to which actions apply.

o   State information or attributes that each object in the task must preserve, display, or allow to be edited.

Identify the objects and actions that appear most often in the workflow.

Make the several most important objects very obvious and easy to manipulate.

Developing Metaphors

A metaphor is a concept where one’s body of knowledge about one thing is used to understand something else. Metaphors act as building blocks of a system, aiding understanding of how a system works and is organized.

Real-world metaphors are most often the best choice. Replicate what is familiar and well known. A common metaphor in a graphical system is the desktop and its components,

o   Choose the analogy that works best for each object and its actions.

o   Use real-world metaphors.

o   Use simple metaphors.

o   Use common metaphors.

o   Multiple metaphors may coexist.

o   Use major metaphors, even if you can’t exactly replicate them visually.

o   Test the selected metaphors.