Simplify the structure of tasks 3 make things visible

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Unformatted text preview: piece of data – confusing two numbers) • Associative Activation Errors (event activates a similar but wrong response) • Loss- of- Activation Errors (forgetting to do something or part of the act) • Mode Errors (when devices have multiple modes and our actions are for the wrong mode) Well designed things should allow us to detect slips by using feedback (a clear discrepancy between actual and intended result). For example, in computers, when destroying a file, it is good to ask for confirmation to verify the user wants to do an irrevocable action) Human cognition is extremely complex and difficult to understand, but better understanding of this will allow us to design better systems with less human error. • Conscious vs. subconscious • Deep / narrow vs. shallow / wide tasks • if shallow, width is acceptable (choosing a flavor of ice cream: many choices, but only one decision) • if narrow, depth is acceptable (following a recipe: few decisions, many steps) Design should allow for human error: 1. Understand causes of error and try to minimize them 2. Make it possible to undo actions 3. Make it easier to discover when errors occur and make them easy to fix 4. Think of tasks as imperfect approximations of what the user wants to do Forcing Functions: If need be, use lockout devices (force a sequence of actions so that the user can’t enter a dangerous place) Chapter 6: The Design Challenge Often good design is an evolving process: a design is tested, problems are found, design is modified. Process repeats and continues until resources run out. Design is a constant battle between usability and aesthetics. Problems occur when one dominates over the other too much. Designers are not end- users, often clients are not either. Often we have selective attention: we focus too much one thing and reduce attention to other vital things. (such as sticking a knife into a toaster to get the...
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This note was uploaded on 01/22/2014 for the course CMS 367 taught by Professor Browning during the Spring '08 term at University of Texas at Austin.

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