摘要:

Program design, from initial idea to executable code, was studied in a group of novice (first programming course) and a group of intermediate (second course) student programmers. The approach of the intermediate students could usually be described as forward and top-down design, but the behavior of the novices could not be so easily captured. Top-down design depends on both the expertise of the programmer and the difficulty of the problem. When faced with a difficult problem, even the expert has to build up a solution from simple pieces. In the approach adopted here, top-down design is based on the refinement of a known solution or schema that is retrieved and expanded at progressively greater levels of detail. If the expert knows all the required abstract and detailed schemas, then the design shows a pattern of top-down and forward expansion at all levels. When a schema cannot be retrieved and has to be created, top-down design breaks down and is replaced by bottom-up design. At the extreme, a rank novice has to create all the required plans, and design then shows consistent bottom-up and backward solution development. Separating plan retrieval from plan creation has three important consequences. First, a model of plan creation shows how knowledge, in the form of plan schemas, is created during the process of program design. Second, plan creation reveals the internal structure of a schema that is hidden in the final program code. Third, the behavior of designers, described as top-down or bottom-up design, may be explained as a result of specific knowledge that is used to design a program.

ISSN:0737-0024    

DOI:10.1207/s15327051hci0601_1

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1991

数据来源: Taylor

摘要:

In this descriptive and exploratory study, 32 users type help requests to what they believe is a computerized advisor. In fact, the advisor is a human mimicking realistic levels of intelligence and knowledge that can be expected from a computerized advisor. Results show that users request help with a very simple and restricted language that is characteristic of language generated under real-time production constraints and of child language. Moreover, users' utterances are frequently ungrammatical. It is hypothesized that these features arise from factors intrinsic to typed advisory situations: Users are performing a primary task under real-time constraints, and typing help requests is a secondary task. On the other hand, users refer to objects and events with very precise descriptions instead of faster-to-type pronouns; they produce very few ellipses and deictic expressions. Future research should elucidate whether shared context between users and computerized advisors needs to be richer than created in this study to sustain the use of expressions whose interpretations depend on context. The tuning of natural language interfaces to the features observed in this study may increase the usefulness of natural language interfaces to advisory systems. The presented methodology is a promising tool for further studies of these factors on users' language.

ISSN:0737-0024    

DOI:10.1207/s15327051hci0601_2

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1991

数据来源: Taylor

摘要:

Traditionally, errors are avoided in training. In contrast to this approach, it is argued that errors can also have a positive function and that one has to learn to deal efficiently with errors on a strategic and an emotional level (error management). An experiment tested these assumptions. One group (n = 9) received guidance for error-free performance; another group (n = 15) received error training. In the latter group, errors were produced by assigning problems that were too difficult to deal with. The error-training group showed higher scores in the nonspeed performance tests. Error training seems to be positive for people with high scores on the cognitive failure questionnaire (Broadbent, Cooper, FitzGerald, & Parkes, 1982).

ISSN:0737-0024    

DOI:10.1207/s15327051hci0601_3

出版商:Lawrence Erlbaum Associates, Inc.    

年代:1991

数据来源: Taylor