Create A Website Ethiopia

If we only look at a single web page, the procedures for using it are typically trivial. So why go to the extra of conducting a task analysis?

The answer, of course, is that web sites are not made up of just one page, and the interactions between users and web pages is not necessarily trivial. We need to consider at least three distinct levels when conducting a task analysis.

• We need to look at the big picture. Who are the user groups that will be using the site, and how do they interact with other users f the site in the course of their overall job responsibilities?

• We need to consider the pages that a single user will navigate to accomplish his or her goals.

• We need to address the procedures that a user will utilize within each of the pages.

If we address only one of the levels, we may make the procedures within each of the pages very simple, but might neglect the possibility that some of the pages may be altogether unnecessary.

We may also fail to see additional improvements that could be made to the overall workflow.

One way to specify the necessary information at each of the levels is to combine use case analysis with hierarchical task analysis.

Use cases document the interactions between different user groups and are used as a first pass at high-level design. The following sections describe use cases, hierarchical task analysis, and their combination into a powerful analysis technique.

Use Cases
Use cases were developed by Ivar Jacobson as a way to analyze software development from the perspective of how a user would typically interact with the system.

Use cases combine a simple way of capturing user scenarios (i.e., instances of how a user might perform a procedure) in a text document and diagramming how different user groups interact while using the system.

They start with the users or actors of a system and describe the activities the actors engage in while using the system. Actors can be users, databases, other companies, or anything else that interacts with your system.

A scenario is the set of steps or actions that an actor must accomplish to achieve a particular goal.

Use cases include the typical, or primary, scenario that the user will go through to accomplish a particular goal and can also include a set of alternative scenarios that the use may go through in atypical situations.

Use cases are easy to work with because most of the necessary information for building a system can be specified in a standard format.

The interaction between different actors in a system can then be captured using use case diagrams. Use case diagrams provide a standard means for viewing an entire transaction in a single view.

Although use cases are a very powerful tool for system development, they have some weaknesses in the design of usable systems. For instance, a use case won’t necessarily tell us if a procedure (scenario) is inefficient.

It also won’t tell us whether our procedures are within the possibilities of human performance or how much training would be required for a person to perform them. These weaknesses exist because use cases were developed as a software development tool.

They are not rooted in human psychology, nor are they intended for that purpose. For many projects, such attention to detail may not be necessary.

For mission-critical or safety-critical tasks, ensuring efficient, error-free performance becomes much more important. For these types of tasks, we turn to hierarchical task analysis.
 

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