Copyright 1999 all rights reserved Why Conduct a Task Analysis? n Uncovered Information may lead to abandoning a bad idea –The world is ready for video telephones –Users want recipe management programs

Copyright 1999 all rights reserved Why Conduct a Task Analysis? n Uncovered information drives the design –without it, we are designing in the dark –keeps us from building a useless program

Copyright 1999 all rights reserved Information Captured Through Task Analysis n User’s goals in performing a task –What are they trying to accomplish? –What subgoals do they generate as a result of their primary goal? –What external representations in the environment help the user to keep track of their goal?

Copyright 1999 all rights reserved Information Captured Through Task Analysis n Work flow patterns –frequency of different tasks performed - how often is A done, B done, etc. –grouping of work tasks - what is done with what

Copyright 1999 all rights reserved Information Captured Through Task Analysis n Work flow patterns –order of work tasks - what is done first, why? –communication patterns - who talks to whom about what –exceptions - when is A not done, why?

Copyright 1999 all rights reserved Information Captured Through Task Analysis n Users’ conceptual model –What is the external representation that is used to do the task - worksheets, patient charts –What organization or model do users keep in their head as they are doing the task?

Copyright 1999 all rights reserved Information Captured Through Task Analysis n User Characteristics –Task experience and knowledge of the domain, e.g., radiologists, bakers, sailors –System experience, e.g., special keys, conventions, syntax, commands, etc. for this system

Copyright 1999 all rights reserved Information Captured Through Task Analysis n User Characteristics –Application experience, e.g., other word processors –Computer literacy, e.g., used word processors, but first time using spreadsheet

Copyright 1999 all rights reserved Task Analysis Methods: Data Gathering n Lots of task analysis methods n None completely satisfactory n Typical Methods –Questionnaires and interviews –Observational studies –Examination of competing, or similar products –Experimental data collection –Unstructured user input

Copyright 1999 all rights reserved Questionnaires and Interviews n Talk to a number of representative users n Talk to key users n Plan interview –Preset questions to address issues identified in advance –Always provide flexibility for additional info –Provide mechanism for recording data easily –Design to have quantitative results

Copyright 1999 all rights reserved Questionnaires and Interviews (continued) n Keep the number of questions low –Only questions with answers that you can’t get other ways –Only questions that will have a direct impact on functional requirements –Avoid asking for everything

Copyright 1999 all rights reserved Questionnaires and Interviews (continued) n Ask clear questions –Can the user understand your question? n Ask questions that users can answer validly and reliably –Does the user store information in this way? –Does the user remember such information? –Will the user be inclined to answer your question truthfully?

Copyright 1999 all rights reserved Observational Studies n Describe and analyze current practice n Note organization of functionality n Note expectations & concerns of users

Copyright 1999 all rights reserved Observational Studies n Collect quantitative data –How many? –How often? –How long? –What order?

Copyright 1999 all rights reserved Study Similar or Competing Products n Incorporate features that users like n Be creative in thinking up possible similar products n Run usability studies on competitors' products

Copyright 1999 all rights reserved Unsolicited Comments from Users n Effective when updating an existing product n Keep track of frequency of comments n Information that is readily available –Internet comments –Suggestions fostered by offering incentives –User hotline conversations

Copyright 1999 all rights reserved Unsolicited Comments from Users n Don’t believe everything users say –Confirm usefulness of suggestions with other techniques –Users have lots of opinions but often do not mentally have access to their performance record users often retype an entire paragraph when it would have been faster to edit itusers often retype an entire paragraph when it would have been faster to edit it retyping is prone to new errorsretyping is prone to new errors