J. Shawn Farris

Factors Affecting the Usefulness of Impenetrable Interface Element Borders

N. Walker and J. B. Smelcer (1990) found that selection times for menus could be reduced by placing the menus adjacent to the edge of the screen; this creates a border between the menu and the edge of the screen that the mouse cursor cannot penetrate. Based on this finding, they proposed that selection times for graphical user interface targets could be reduced by employing these impenetrable borders. Four studies tested this prediction with a Web browsers back button and scroll bar. Results demonstrated that targets employing impenetrable borders were always selected faster than were targets placed 1 pixel from the edge of the screen, which supports Walker and Smelcers prediction. However, within the constraints of the current studies, this speed advantage asymptotes at approximately 283 ms for target heights of 2.00 cm and target distances of 3.50 cm. In addition, these findings generalized across most angles of approach. Actual or potential applications of this research include target placement decisions in the design or modification of graphical user interfaces.

Why Does the Negative Impact of Inconsistent Knowledge on Web Navigation Persist

Farris (2003) discovered that users had greater difficulty finding information on a Web site when their prior knowledge was inconsistent with the Web sites content, relative to when their knowledge was consistent with it. In addition, he found that this difficulty was persistent over trials. To explain this persistence, Farris offered a schema-based account, which instantiated inconsistency in a single manner. These studies tested 2 predictions that were derived from Farriss account. Specifically, Experiment 1 assessed whether schema elaboration would be gradual, whereas Experiment 2 assessed whether task repetition would eliminate the negative impact of inconsistent knowledge. The results associated with navigation efficiency supported the predictions derived from Farriss account. The results associated with the choices made by participants as they navigated the site, however, contradicted the predictions. A new account, based on production-rules rather than schemata, is offered that considers both sets of results, because it instantiates inconsistency in more than 1 manner. This new account has implications for the design and redesign of Web sites.

Selection of Web Browser Controls with and without Impenetrable Borders: Does Width Make a Difference?

Graphical user interface elements can be selected faster if they are placed against the edge of the screen. Doing so creates an impenetrable border between the element and the edge of the screen that the mouse cursor cannot penetrate, which changes how users move the mouse resulting in quicker selection times. This study assessed the influence of visible width on selection time when targets did or did not have impenetrable borders. Ten participants selected targets that varied in Target Type (with or without impenetrable borders), Width (1, 2, 3, 4, 5 cm), and Distance (2, 4, 8, 16, 32 cm). For a given width, targets with impenetrable borders were always selected faster than targets without impenetrable borders. Also, increasing the width of targets with impenetrable borders had little effect on selection time, whereas doing so when targets did not have impenetrable borders resulted in a substantial effect on selection time. The results indicate that a 1 cm wide target is adequate to make use of the advantage of edge targets in GUI design.

Examining Information Searching on the World Wide Web with a Screen-Reader: A Verbal Protocol Analysis

Recently, assistive devices designed for computer systems have proliferated, including those designed to support users with visual impairments (i.e., screen-readers). However, research examining how individuals use screen-readers to access the Internet is virtually non-existent. Therefore, the purpose of the reported study was to examine the behavior of a user with visual impairment, via protocol analysis, while using the World Wide Web to find information. We classified her behavior into an HCI-relevant model, i.e., Normans (1988) seven stages of action, in order to identify potential usability bottlenecks. The results indicated that executing actions and, more notably, interpreting the system state were the most frequent and time-consuming tasks. In addition, the results suggested that the user had difficulty determining the effects of her control inputs on system status, as well as determining whether or not goal-relevant information was present on the current page. For screen-reader design, this suggests that there are possible usability problems in interfacing the user with the screen-reading software and the way textual information is aurally displayed to the user.

Using Impenetrable Borders in a Graphical Web Browser: Are All Angles Equal?

Impenetrable borders can be created by placing graphical user interface targets (e.g., buttons, scroll bars, etc.) on the edge of a computer display. Research demonstrated that targets with impenetrable borders (edge targets) are selected faster than targets of the same size that are not against the edge of the screen (non-edge targets). This paper discusses the reasons why edge targets are selected faster than non-edge target and points out a critical weakness in past research on impenetrable borders. Specifically, researchers have always placed targets at a 90° angle from the cursors origin, thus forgoing any ecological validity. Accordingly, an experiment is reported that tests the effectiveness of impenetrable borders when approach angle varies on a graphical web browser interface. Results indicate that impenetrable borders are effective across all of the approach angles used. These results support the recommendation to place commonly used targets at the edge of the screen whenever possible.

Using Impenetrable Borders in a Graphical Web Browser: How Does Distance Influence Target Selection Speed?

Impenetrable borders are edges of graphical user interface targets (e.g., buttons, scroll bars) that the mouse cursor cannot cross. Research has shown that targets with impenetrable borders (edge targets) are selected faster than targets without impenetrable borders (non-edge targets). In addition, prior research determined that the effectiveness of impenetrable borders is maximal between .50 and 11.75 cm distance from the cursors origin to the target. However, this is a broad range and a more specific estimate of distance would be useful for designers wishing to maximize the effectiveness of impenetrable borders. Accordingly, the reported experiment searched for the critical distance where impenetrable border effectiveness asymptotes using a graphical web browser interface. Results indicate that impenetrable border effectiveness asymptotes between .50 cm and 3.50 cm distances. These results support past research and make a more detailed design recommendation. An example of a redesigned interface incorporating impenetrable borders is given.

The Human-Web Interaction (HUWI) Cycle: A Framework of Users' Perception, Action, and Cognition on the Web

Since its inception, the World Wide Web has flourished. While advances have been made in the general area of web usability, little attention has been paid to developing theories of human-web interaction. Accordingly, Neissers (1976) perceptual cycle, which unifies research on action, perception, and cognition, is used as a framework for a human-web interaction (HuWI) cycle. The HuWI cycle assumes that while users interact with a website, in order to locate certain pieces of information, they sample only goal-relevant information from the website. Users then modify their knowledge of the system, based on the goal-relevant information that was acquired. This newly modified system knowledge then directs their interaction further.

Is Practice Necessary to Speed the Selection of Web Browser Controls that Have Impenetrable Borders

Previous research demonstrated that interface elements could be selected faster when placed against the edge of the screen. Doing so creates an impenetrable border between the element and the edge of the screen that the mouse cursor cannot penetrate. This changes how users move the mouse, so that selection quickens. This study investigated the effect of practice on the acquisition of targets with and without impenetrable borders. Ten participants selected targets that varied in Target Type (with or without impenetrable borders), and Distance (.5, 3.5, 6.5, 9.5, and 12.5 cm) across five Practice Sessions. The results confirmed that targets with impenetrable borders were selected faster than targets without impenetrable borders and that participants demonstrated consistent reductions in selection time over sessions, regardless of the target type. In addition, excessive practice was not necessary to demonstrate target type differences; thus the advantage of having impenetrable borders seems to be relatively instantaneous.

Internet-Based Distance Education Materials: Does Writing Style Matter?:

How can distance educators format materials so that they maximize usability and optimize learning? Several web-writing characteristics have been identified that address these questions. “Objective” writing, most analogous to educational text, presents information without exaggerations or boasting. “Concise” and “scannable” writing omit superfluous information and support visual scanning by highlighting key features, respectively. “Combined” writing aggregates characteristics from the objective, concise, and scannable styles. Previous research suggests that, in contrast to results from the commercial domain, these writing styles do not influence memory of distance education materials. This discrepancy is possibly due to measurement differences. To address this issue, the present study employed recognition (i.e., multiple-choice) and guided recall (i.e., fill-in-the-blank) tasks in order to assess the efficacy of the writing styles in a distance education context. The results, however, confirmed the earlier findings, i.e., regardless of the materials writing format, memory for web site content was unaffected.

An Investigation of Web Writing Styles and Distance Education

Increasingly, the Internet is being seen as a vehicle for distance education. However, this medium presents new challenges for developers of distance education content. For example, do we read material on the Web the same way that we read from paper? Is there a different writing style for web-based information that facilitates on-line reading? This study explored four different writing styles in either a printed or on-line format. Examination of free recall from 80 undergraduates indicated that fewer idea units were correctly recalled for the concise writing style than the scannable, objective, and combined writing styles within the Web medium. In addition, in the paper format, more idea units were correctly recalled with the combined writing style than the scannable and objective writing styles. These results may be driven by the reading behavior associated with a distance education task. Possible limitations and suggestions for future research are provided.