Scott d. Wood

Predictive engineering models based on the EPIC architecture for a multimodal high-performance human-computer interaction task

Engineering models of human performance permit some aspects of usability of interface designs to be predicted from an analysis of the task, and thus they can replace to some extent expensive user-testing data. We successfully predicted human performance in telephone operator tasks with engineering models constructed in the EPIC (Executive Process-Interactive Control) architecture for human information processing, which is especially suited for modeling multimodal, complex tasks, and has demonstrated success in other task domains. Several models were constructed on an a priori basis to represent different hypotheses about how operators coordinate their activities to produce rapid task performance. The models predicted the total time with useful accuracy and clarified some important properties of the task. The best model was based directly on the GOMS analysis of the task and made simple assumptions about the operators task strategy, suggesting that EPIC models are a feasible approach to predicting performance in multimodal high-performance tasks.

GLEAN: a computer-based tool for rapid GOMS model usability evaluation of user interface designs

Engineering models of human performance permit some aspects of usability of interface designs to be predicted from an analysis of the task, and thus can replace to some extent expensive user testing data. The best developed such tools are GOMS models, which have been shown to be accurate and effective in predicting usability of the procedural aspects of interface designs. This paper describes a computer-based tool, GLEAN, that generates quantitative predictions from a supplied GOMS model and a set of benchmark tasks. GLEAN is demonstrated to reproduce the results of a case study of GOMS model application with considerable time savings over both manual modeling as well as empirical testing.

Predictive engineering models using the EPIC architecture for a high-performance task

Engineering models of human performance permit some aspects of usability of interface designs to be predicted from an analysis of the task, and thus can replace to some extent expensive user testing data. 5/22/13 4:56 PM Predictive Engineering Models Using the EPIC Architecture for a High-Performance Task Page 2 of 10 http://www.sigchi.org/chi95/proceedings/papers/dek_bdy.htm Human performance in telephone operator tasks was successfully predicted using engineering models constructed in the EPIC (Executive Process-Interactive Control) architecture for human informationprocessing, which is especially suited for modeling multimodal, complex tasks. Several models were constructed on an a priori basis to represent different hypotheses about how users coordinate their activities to produce rapid task performance. All of the models predicted the total task time with useful accuracy, and clarified some important properties of the task.

User Needs Analysis

This chapter discusses the methods for understanding the user needs early in the product development cycle and how these methods can help user experience practitioners understand workflow, improve efficiency, and eliminate weak areas that cause hindrance. User needs analysis sets the foundation for the entire design process. The principal purpose of this stage of design is to define the design goals and constraints and develop an understanding of the audience and what they do. User needs analysis involves four primary activities including investigation, analysis, specification, and documentation. The functional specs are referenced throughout the design and production of the site to verify that the system being produced corresponds to the necessary functionality. Several forms of background research are used to uncover user needs such as surveys, scenarios, competitive analysis, interviews, and focus groups. These give a better idea about true user profile, user needs, and user preferences. Task analysis can also be performed to specify how the information and functionality found in the requirements analysis will be used. In addition to codifying user procedures, task analysis can also be used as a design tool.

Website design from the trenches

Most website design projects involve small to mediumsized sites consisting of between ten and fifty pages. Such projects require designers to operate on a tight schedule and a very limited budget. With tightly constrained resources, how can we maintain a high standard of design and create usable and useful products? This tutorial presents a practical approach to applying usability techniques in website design. Our design process includes techniques for project management, dealing with clients, sketching and comping techniques for quickly producing high-quality alternatives, and a set of website design guidelines.

An EPIC model for a high-performance HCI task

EPIC is an architecture for computational models of human information processing that incorporates current results and theories from human performance. It combines detailed processors for different modalities with a production-system cognitive processor. An EPIC model was constructed for telephone operator tasks based on one protocol and then was validated against two other protocols for similar tasks. Total execution time and detailed keystroke-level inter-event times were predicted with good accuracy. It should be possible to construct such models on a routine basis to predict performance of interface designs involving multiple modalities and time-critical tasks.

Practical usability methods in website design

This tutorial presents a practical approach to applying usability methods to website design. Website projects are usually done on tight schedules, with limited resources, and without a well-defined approach for achieving usability. For many developers its easy to dismiss usability methods as an unnecessary overhead cost. We demonstrate how usability methods can be integrated efficiently and effectively into each stage of the website design process. Employing this process, and by using forms, checklists, and other tools to improve communication and workflow, website projects can be managed successfully achieving a highly-usable product.

CHAPTER 2 – User Needs Analysis

Publisher Summary This chapter discusses the methods for understanding the user needs early in the product development cycle and how these methods can help user experience practitioners understand workflow, improve efficiency, and eliminate weak areas that cause hindrance. User needs analysis sets the foundation for the entire design process. The principal purpose of this stage of design is to define the design goals and constraints and develop an understanding of the audience and what they do. User needs analysis involves four primary activities including investigation, analysis, specification, and documentation. The functional specs are referenced throughout the design and production of the site to verify that the system being produced corresponds to the necessary functionality. Several forms of background research are used to uncover user needs such as surveys, scenarios, competitive analysis, interviews, and focus groups. These give a better idea about true user profile, user needs, and user preferences. Task analysis can also be performed to specify how the information and functionality found in the requirements analysis will be used. In addition to codifying user procedures, task analysis can also be used as a design tool.

Pre-Launch and Post-Launch

This chapter reviews the procedures that should accompany the approach to the launch as well as ways to track and target changes once the Web site is up and running. The steps involved in launching a site are as critical and relevant to success as requirements analysis, writing, or page layout. Just prior to the launch, extensive final quality assurance is required, and at launch, several critical items must be tested. After launch, it is necessary to promote and maintain the site and to continue testing and evaluating its performance. A prelaunch schedule can keep progress on track and remind the owner of the smaller issues that often lead to delays. Testing aside, some preparation is necessary for the final launch date. One of the crucial planning steps is to make sure to select and register the domain name before launch. Quality assurance (QA) processes should occur throughout the production process. QA needs to start at the beginning of a project and never end. While QA is continuous, it reaches its pinnacle in the final stages of the production process before the Web site is launched.

Target Audience and Target Platforms

This chapter looks at defining who the users are. In understanding the target audience, the need is not only to understand specific personal attributes, but also to understand what types of computers and software they are using, that is, the target platform. Specific discussions are offered on the ways people vary. Market segment, disabilities, education, and experience are examples of individual differences that can have an effect on user needs. There are differences in user preference settings and international differences. Beyond differences in people, there are hardware and software differences in the areas of operating systems, monitors, browsers, and networks. A scenario is an approach for clarifying exactly who these people are. The goal of a scenario is to make sure that the site is not merely theoretically usable, but that it actually serves the needs of specific people in real life. A scenario brings out additional functional requirements and ideas for the user interface that are driven by user profiles and context. This audience specification can be used for recruiting potential users for surveys and user testing, so the demographics should be clear enough to reproduce accurately.