Teacher verbal behavior following student success and failure

Undergraduate subjects taught identifying traits of animals (fish, reptiles, amphibians, mammals) to a fifth grade student confederate over a microphone. Subjects were randomly assigned to one of four conditions in which they failed (F) or succeeded (S) in teaching five animal comparison problems. The four conditions were (a) F, S, S, S, S; (b) F, F, F, S, S; (c) S, F, F, F, S; and (d) S, S, S, F, S. The teaching sessions were tape recorded and analyzed for Teaching Time, Word Rate, and Voice Amplitude. Analyses revealed increased Teaching Time and decreased Word Rate following failure. Voice Amplitude increased across teaching sessions independent of success or failure. Findings were interpreted as more consonant with frustration-aggression than frustrative nonreward energizing theory.     

SOURCES OF THE PUBLIC AGENDA:THE PRESIDENT-PRESS-PUBLIC RELATIONSHIP

This agenda-setting study explores ways that individuals processinformation issues by examining two potential public agendasources: the news media and the president of the USA. The researchersused a two-site study to examine the magnitude of influencefrom media exposure and perceived credibility of source. Itwas found that the higher the level of exposure to media anda presidential state-of-the-union message, the more likely thatissues were considered important. However, when both were examinedsimultaneously, media exposure was the more powerful predictor.Source credibility, both of the media and the president, wasalso found to influence how people perceived the importanceof issues.     

Semantically assisted medical bibliographic retrieval: an experimental computer system

An experimental computer-based bibliographic retrieval system has been implemented to explore how semantic (conceptual) relationships between MeSH terms might assist the retrieval process. To construct the experimental system's database, lists of abstracts were produced using MEDLINE. Each list contained papers discussing a specified pair of terms. Each abstract was then analyzed to determine the specific relationship(s) between the two terms discussed in that paper. The project then explored how these semantic relationships could be incorporated into the computer to enhance bibliographic retrieval.     

Methods for estimating the number of relevant documents in a collection

Several statistical sampling methods are evaluated for estimating the total number of relevant documents in a collection for a given query. The total number of relevant documents is needed in order to compute recall values for use in evaluating document retrieval systems. The simplest method considered uses simple random sampling to estimate the number of relevant documents. Another type of random sampling, which assigns unequal selection probabilities to the individual documents in the collection, is also investigated. An alternative approach considered uses curve fitting and extrapolation, where a smooth curve is developed which relates precision to document rank. Another curve relates a function of precision to the query-document score. In either case, the curve is extrapolated to the total number of documents in order to estimate the number of relevant documents. Empirical comparisons are made of all three methods.