Cognitive engineering

Usability Testing Essentials provides readers with the tools and techniques needed to begin usability testing or to advance their knowledge in this area. The book begins by presenting the essentials of usability testing, which include focusing on the user and not the product; knowing when to conduct small or large studies; and thinking of usability as hill climbing. It then reviews testing options and places usability testing into the context of a user-centered design (UCD). It goes on to discuss the planning, preparation, and implementation of a usability test. The remaining chapters cover the analysis and reporting of usability test findings, and the unique aspects of international usability testing. This book will be useful to anyone else involved in the development or support of any type of product, such as software or web developers, engineers, interaction designers, information architects, technical communicators, visual or graphic designers, trainers, user-assistance specialists, and instructional technologists.

Usability Testing Essentials: Ready, Set...Test!

The worst case fall time is given by tf = 2.2 (2Rn•Cout + Rn•Cx) = 2.2(2*1 KΩ*8fF + 1KΩ*2fF) = 39.6ps b) The best-case rise time for a NAND gate occurs when both pMOS turn on and is given by tr = 2.2 (Rp/2) •Cout, where the total parallel resistance is Rp/2. = 2.2 * 2 KΩ/2 * 8 fF = 17.6 ps c) The worst-case rise time of a NOR gate is given by tr = 2.2 (2Rp•Cout + Rp•Cx) = 2.2(2*2 KΩ*8fF + 2KΩ*2fF) = 79.2 ps

Problem (2)

Problem (1)

To better support usability practice, most usability research focuses on evaluation methods. New ideas in usability research are mostly proposed as new evaluation methods. Many publications describe experiments that compare methods. Comparisons may indicate that some methods have important deficiencies, and thus often advise usability practitioners to prefer a specific method in a particular situation. An expectation persists in human–computer interaction (HCI) that results about evaluation methods should be the standard “unit of contribution” rather than favoring larger units (e.g., usability work as a whole) or smaller ones (e.g., the impact of specific aspects of a method). This article argues that these foci on comparisons and method innovations ignore the reality that usability evaluation methods are loose incomplete collections of resources, which successful practitioners configure, adapt, and complement to match specific project circumstances. Through a review of existing research on methods and re...

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Ingredients and Meals Rather Than Recipes: A Proposal for Research That Does Not Treat Usability Evaluation Methods as Indivisible Wholes

Although usability practitioners have successfully applied usability engineering processes to increase the usability of interaction designs, the literature suggests that usability practitioners experience a number of difficulties that negatively impact the effectiveness of their work, which in turn affects the effectiveness of the usability engineering processes within which they work. These difficulties include identifying and recording critical usability data and understanding and establishing relationships among usability data. These difficulties are particularly pronounced for novice usability practitioners. One approach to addressing these difficulties is through appropriate usability engineering tool support. We argue that existing usability engineering tools offer excellent support for helping experienced usability practitioners more efficiently do their jobs, but they provide little support for helping novice usability practitioners more effectively do their jobs. We introduce a tool feature, usability problem instance records, to better support novice usability practitioners. We describe the results of a study of this feature, which suggest that the feature helps to improve two aspects of the effectiveness of novice usability practitioners: reliability and quality.

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Supporting novice usability practitioners with usability engineering tools

Much research has been devoted to developing usability evaluation methods that are used in evaluating interaction designs. More recently, however, research has shifted away from evaluation methods and comparisons of evaluation methods to issues of how to use the raw usability data generated by these methods. Associated with this focus is the assumption that the transformation of the raw usability data into usability information is relatively straightforward. We would argue that this assumption is incorrect, especially for novice usability practitioners. In this article, we present a structured process for transforming raw usability data into usability information that is based on a new way of thinking about usability problem data. The results of a study of this structured process indicate that it helps improve the effectiveness of novice usability practitioners.

Rex Hartson

Papers

Supporting novice usability practitioners with usability engineering tools

A structured process for transforming usability data into usability information