The problem of modeling information systems is studied with a focus on predictability. Syntactic, semantic, and pragmatic criteria are discussed, and 11 references are cited. (Author/BK)

Discusses the need for a method to measure computer user abilities, and presents an instrument that identifies individuals' technical, modeling, and applications skills. An evaluation of the instrument in terms of validity and reliability is reported, and applications in user education research are suggested. (12 references) (CLB)

Discussion of the use of scientific information disseminated in primary subject literature focuses on a study that developed a methodology for hypothesis testing that measured document obsolescence by means of citation analysis and content obsolescence by expert opinions and then compared the results. Information validity and information utility…

Describes two experiments that were conducted at the University of Illinois to determine how cognitive abilities of users of information retrieval systems and specific design features combine to create system usability. Logical reasoning and perceptual speed are examined, and reliability and validity are discussed. (Contains 12 references.) (LRW)