- From: Lloyd G. Rasmussen <lras@loc.gov>
- Date: Wed, 06 Oct 1999 00:09:04 -0400
- To: w3c-wai-ua@w3.org
>This was forwarded through our LOC web design mailing list. Maybe you've already seen it. If not, it looks like good ammo for the user agent working group meeting. > -- Lloyd > > >>Approved-By: "Elizabeth F. Miller" <emil@LOC.GOV> >>Date: Fri, 24 Sep 1999 07:55:04 -0400 >>Reply-To: "Library of Congress HTML Users' Forum" <HTML@loc.gov> >>Sender: "Library of Congress HTML Users' Forum" <HTML@loc.gov> >>From: "Elizabeth F. Miller" <emil@loc.gov> >>Subject: UI Design Update newsletter - September, 1999 (fwd) >>Comments: To: html@loc.gov >>To: Multiple recipients of list HTML <HTML@RS8.LOC.GOV> >> >>---------- Forwarded message ---------- >>Date: Thu, 23 Sep 1999 11:56:29 -0500 >>From: hfi@humanfactors.com >>To: Newsletter@humanfactors.com >>Subject: UI Design Update newsletter - September, 1999 >> >>USER INTERFACE DESIGN UPDATE - September, 1999 >> >>Insights from Human Factors International, Inc. (HFI) >>Providing consulting and training in software ergonomics. >>(http://www.humanfactors.com/home/) >> >>Every month HFI reviews the most useful developments in >>UI research from major conferences and publications. >>__________________________________________________ >> >>In this issue Dr. Bob Bailey reviews: >> >>1. Multimedia and Working Memory Limitations - with complex >> tasks, working memory capacity can be "increased" by using >> two senses rather than one. >> >>2. Using Multimedia in Instruction - some guidlelines. >>__________________________________________________ >> >>1. MULTIMEDIA AND WORKING MEMORY LIMITATIONS - >>When Two Sensory Modes are Better than One, Tindall-Ford, S., >>Chandler, P. and Sweller, J., Journal of Experimental Psychology: >>Applied, 3(4), 257-287 (1997). >> >>With designing user interfaces, when is it better to take the time to >>allow users to use two rather than one sense? In other words, when >>is there a human performance advantage of having users both read >>and hear information? >> >>Tindall-Ford, Chandler and Sweller (1997) compared the >>performance outcome when participants read text and evaluated >>visual diagrams (visual-only), versus heard text and evaluated visual >>diagrams (auditory and vision). They postulated that any improved >>performance was due primarily to an effective expansion of >>"working memory" limitations. Human working memory consists >>of both a visual-spatial sketch pad for dealing with visual material >>(text, pictures, diagrams), and a phonological loop for dealing with >>auditory information. These two processors are assumed to >>operate independently. >> >>Several past studies were reviewed. They showed that: >> >>1. People were better able to carry out two tasks simultaneously >> (repeating spoken words and learning new words) if each task >> involved a different modality (visual vs. auditory), >> >>2. People were presented with a verbal description of a layout >> that was sufficiently complex to be unintelligible unless visualized. >> The description was presented either in auditory form or >> simultaneously in auditory and written form. The auditory-alone >> mode resulted in superior performance. >> >>3. Two groups of children were asked to either listen to or read >> a story. Half of each group were instructed to visualize the story >> while it was being presented. On a test given after the story, the >> "visualizers" performed better, but only those that listened to, not >> those that read the story. >> >>These findings suggest that in certain, complex situations working >>memory capacity can be "increased" by using two senses rather >>than one. For example, performance can be substantially degraded >>when people must attend to multiple sources of information that >>must be mentally integrated before meaning can be derived. Thus, >>designers should present information to users in ways that reduces >>the need for mental integration, and consequently reduces the >>demands on working memory. >> >>Tindall-Ford, et.al., conducted three experiments using electrical >>trade apprentices. In the first study, one group learned by using a >>diagram and separated written text, a second group used a diagram >>and integrated written text, and a final group used a diagram and >>auditory instructions. The latter two groups performed reliably >>better because their working memory resources were not exceeded. >> >>In the second study they evaluated user performance on a complex >>task when using: >> >> (a) a table and related text, versus >> (b) a table with an auditory explanation. >> >>The visual-audio group performed reliably better; again, because >>of the reduced load on working memory. >> >>In the third study, they had participants either look at diagrams >>and read instructional materials (visual-only) or look at diagrams >>while listening to instructional material (audio-visual). They >>performed two easy tasks and one difficult task. In the easy tasks >>there were no differences between visual-only and visual-audio. >>In the difficult task, the participants using two senses (vision and >>hearing) performed reliably better. >> >>This article makes a strong case for having designers take the time >>to physically integrate information in computer systems, i.e., put >>all required information within close proximity. When this is not >>possible, and when the task is complex, working memory capacity >>can be extended by presenting information using both visual and >>auditory modes. >>__________________________________________________ >> >>3. USING MULTIMEDIA IN INSTRUCTION - Guidelines for >>the Use of Multimedia in Instruction, Williams, J. R., Proceedings >>of the Human Factors and Ergonomics Society 42nd Annual >>Meeting, 1447-1451 (1998). >> >>Williams (1998) reviewed the literature on using multimedia in >>instruction. He extracted numerous guidelines on the effective use >>of multimedia after reviewing about 100 literature sources. One >>of his many discussions was a section on using combined visual >>and verbal information. >> >>In general, the past research seems to indicate that combining >>visual and verbal (auditory) information can lead to enhanced >>comprehension, when compared to their use alone (see the Tindall- >>Ford, et.al., article discussed above). But designers also should be >>aware that having both visual and audio modes may result in no >>performance improvements (if the task is too simple), and may >>or may not increase user satisfaction. >> >>Some guidelines: >> >>-- Past research suggests that visual and narrative information >> should be presented simultaneously, or the visuals should >> precede the narrative by no more than seven seconds. >> >>-- Both the visual and auditory information should be totally >> relevant to the task being performed. >> >>-- When words are spoken, the content should be simple, >> and the speed of narration should be about 160 words per >> minute. The narration should be slowed when used to >> introduce new ideas or concepts. >> >>-- Off-screen narration should be used rather than on-screen >> narration, unless the narrator is a recognized authority on >> the topic. >>__________________________________________________ >> >>NOTE FROM BOB: If there are any references you feel are >>important to include in the Annual User Interface Update - 2000, >>or in future newsletters, please let us know. They could be either >>published articles, conference proceedings, or internal research >>papers. Send references to mailto:hfi@humanfactors.com. >>__________________________________________________ >> >>3-day 1999 Annual User Interface Update Seminar presented by >>Dr. Robert Bailey. >>http://www.humanfactors.com/training/annualupdate.asp. >> >> >>Register for UI Update Seminar in Seattle - November 2-4/99. >>https://www.humanfactors.com/training/registration/AUregister8.asp >>__________________________________________________ >> >>Suggestions, comments, questions? >>HFI editors at mailto:hfi@humanfactors.com. >> >>Want past issues? >>http://www.humanfactors.com/library/pastissues.asp >> >>Subscribe? - http://www.humanfactors.com/library/subscribe.asp >> >>Do NOT want this newsletter? >>E-mail mailto:unsubscribe@humanfactors.com with a Subject of: >>"Unsubscribe Newsletter" >> Lloyd Rasmussen, Senior Staff Engineer National Library Service f/t Blind and Physically Handicapped Library of Congress (202) 707-0535 <lras@loc.gov> <http://www.loc.gov/nls/> HOME: <lras@sprynet.com> <http://lras.home.sprynet.com
Received on Wednesday, 6 October 1999 01:21:56 UTC