摘要:

Animated demonstrations display the execution of interface procedures. They appear to be a natural and fast way for users to learn direct-manipulation interfaces by watching. To assess their effectiveness for users learning HyperCard™, we compared carefully matched animated demonstrations, procedural textual instructions, and demonstrations combined with spoken procedural text. During training, demonstration users were faster and more accurate than text-only users. Without the instructions, 7 days later, text-only users were faster and as accurate as demonstration users in recalling and performing identical and similar tasks without the instructions. Surprisingly, users of the combined demonstrations with spoken text closely mirrored the results of the demonstration-only users. The poor retention and transfer for the demonstration users appeared to be due to mimicry of the demonstrated procedures. Even with accompanying spoken text, the simplicity of using animated demonstrations may encourage superficial processing and disregard for the procedural text.

ISSN:0737-0024    

DOI:10.1207/s15327051hci0803_1

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1993

数据来源: Taylor

摘要:

Student groups completed a rank-ordering task in a "low-structure" computerized meeting room where all group members had equal access to a shared computer with a large monitor. Strategies used by the groups to distribute control over the public monitor, determinants of which members took control, and the consequences of control strategies were examined. Groups adopted either a dedicated-scribe strategy, in which one member had control throughout the session, or a non-dedicated-scribe strategy, in which control of the public monitor passed among members. Groups with at least one member who had low proficiency with the technology were very likely to adopt a dedicated-scribe strategy. Social influence within the group, proficiency with the computer system, and gender predicted which group members would take control of the public monitor. The results suggest that a group's social structure may be altered by the use of low-structure computer support, depending on the distribution of technical proficiency in the group. Dedicated-scribe groups had marginally better task performance but reported less increase in satisfaction (over previous work together) than non-dedicated-scribe groups. The implications of this research for the design and use of group computer support are discussed.

ISSN:0737-0024    

DOI:10.1207/s15327051hci0803_2

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1993

数据来源: Taylor

摘要:

Project Ernestine served a pragmatic as well as a scientific goal: to compare the worktimes of telephone company toll and assistance operators on two different workstations and to validate a GOMS analysis for predicting and explaining real-world performance. Contrary to expectations, GOMS predicted and the data confirmed that performance with the proposed workstation was slower than with the current one. Pragmatically, this increase in performance time translates into a cost of almost $2 million a year to NYNEX. Scientifically, the GOMS models predicted performance with exceptional accuracy. The empirical data provided us with three interesting results: proof that the new workstation was slower than the old one, evidence that this difference was not constant but varied with call category, and (in a trial that spanned 4 months and collected data on 72,450 phone calls) proof that performance on the new workstation stabilized after the first month. The GOMS models predicted the first two results and explained all three. In this article, we discuss the process and results of model building as well as the design and outcome of the field trial. We assess the accuracy of GOMS predictions and use the mechanisms of the models to explain the empirical results. Last, we demonstrate how the GOMS models can be used to guide the design of a new workstation and evaluate design decisions before they are implemented.

ISSN:0737-0024    

DOI:10.1207/s15327051hci0803_3

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1993

数据来源: Taylor