Search (7 results, page 1 of 1)

  • × author_ss:"Chan, H.C."
  • × year_i:[1990 TO 2000}
  1. Chan, H.C.; Goldstein, R.C.: User-database interaction at the knowledge level of abstraction (1997) 0.02 
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    Abstract
    Proposes and develops a new level of user-database interaction, the knowledge-level interface, where the user and the database system exchange only knowledge from the user. Under the new KL approach, the database system is no longer seen as a store of data. It is an agent to hold domain knowledge and provide it upon request
    Date
    22. 1.1999 19:06:09
    Type
    a
  2. Chan, H.C.; Wei, K.K.; Siau, K.L.: ¬An empirical study on end-users' update performance for different abstraction levels (1994) 0.00 
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    Abstract
    A major database task is update, for which performance has not been measured. With the widespread availability of databases, updates will be done frequently by end users. The task is gaining in importance as a measure of the usabiblity of a database system. An experiment was conducted to measure the effect of different abstraction levels on user performance for updates. A conceptual level group used the entity relationship model with an entity relationship query language KQL, while a logical level group used the relational model with the standard relational language SQL. Performance was primarily measured by the accuracy of the update query. Secondary measures of time and confidence were also taken
    Type
    a
  3. Chan, H.C.; Wei, K.K.; Siau, K.L.: ¬A system for query comprehension (1997) 0.00 
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    Abstract
    A major difficulty of query writing for databases is that users do not fully understand queries. Proposes a system providing feedback to enable users to better understand their queries. It is a multi-functional rule-based system. In addition to providing an English translation for the query, it pin-points syntax errors, and suggests possible solutions. Finds likely semantic errors, and provides possible solutions. The system was implemented for a query language based on the entity relationship model. It is expected to lead to better user performance. Empirical testing showed significant improvement in user performance with the feedback system. The system can be used for computer-aided training and in actual operation
    Type
    a
  4. Chan, H.C.; Wei, K.K.: User query performance with database feedback (1999) 0.00 
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    Type
    a
  5. Chan, H.C.; Tan, B.C.Y.; Wei, K.L.: Three important determinants of user performance for database retrieval (1999) 0.00 
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    Type
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  6. Chan, H.C.: Naturalness of graphical queries based on the entity relationship model (1995) 0.00 
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    Abstract
    Graphical queries involving 14 different query concepts were used in a study with 27 subjects. The results show that well designed graphical queries can be comprehended without teaching. Not so well designed queries are difficult to comprehend. The natural ability to specify graphical queries is not as good. The results identify clearly those concepts that are naturally easy to specify, and those that are difficult. The findings can be used for designing graphical interfaces, as well as for designing training packages
    Type
    a
  7. Chan, H.C.; Wei, K.K.: Effect of grading schemes on outcomes in query writing experiments (1996) 0.00 
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    Type
    a

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