Reasons for Student Engagement in Extra-Class Communication

This study extends instructional communication research on extra-class communication (ECC) by presenting an integrative analysis comparing the explanatory utility of student- and instructor-oriented reasons for student engagement in frequent ECC. Results from 495 college students suggested that student-oriented reasons, specifically the relational and functional student motives, were the only significant, positive predictors of students’ perceptions of frequent ECC engagement. Other student motives (excuse making, participation, sycophancy) and perceptions of instructor approachability did not significantly predict perceived frequency of ECC engagement.     

Another Look at What Moves Public Opinion: Media Agenda Setting and Polls in the 2000 U.S. Election

This study examined two levels of media agenda effects on aggregatepublic opinion from different news sources. The effects wereinvestigated immediately and cumulatively. Content analysisdata from the 2000 U.S. presidential election coverage by fournational news organizations were related to the Gallup pre-electionpoll standings of each candidate. Regression analyses foundthat both the salience of a candidate and the salience of theattributes of a candidate cumulatively, but not immediately,influenced his standing in the polls. An analysis of news sourcessupported the finding that the two levels of agenda-settingeffects seemed mostly cumulative rather than immediate. Newsfrom different sources, however, tended to have effects of differentdegrees and sometimes different directions on candidate pollstandings. Cumulative effects of candidate salience on aggregateopinion change were found for non-partisan and neutral newssources—reporters, poll reporting and public documents—whereasthe effects of candidate attribute salience mostly came frompartisan sources—the candidate himself and members ofthe competing political party. Possible political implicationsof these findings are discussed.     

Design of minimum sensitivity multiple loop feedback bandpass active filters

A method is described for determining multiple loop feedback topologies which yield minimum sensitivities for symmetrical, all-pole bandpass filters. The procedure begins with a follow-the-leader feedback (FLF) topology and additional feedback loops are constructed until minimum sensitivity is achieved. Filters comprised of identical second-order sections and non-identical sections, respectively, are considered.     

Cultured pearls—commercialised biomineralisation

At the turn of the last century there was an ever increasing world demand for pearls while at the same time their known fishing grounds were becoming exhausted. Some way of artificially increasing their production was obviously desirable, and the problem attracted considerable effort. It was an attempt to exploit a scientifically poorly understood phenomenon, and it is interesting, in retrospect, to relate these attempts to recent concepts of biomineralisation. Pearls are, of course, the layers of aragonitic calcium carbonate secreted by molluscs.     

A prototype grammar kit in PROLOG

This article presents a prototype of a computerized grammar kit written in PROLOG and implemented on a LISP machine. The kit consists of tools and examples intended to be used by children interested in exploring language. A grammar written in PROLOG using this tool kit can be used not only to parse, but also to generate, sentences. A serious shortcoming of PROLOG for children is that when a program misbehaves one must understand its complex operational semantics. A major tool in the grammar kit to alleviate this problem is a dynamic graphical tracer which uses a backtracking turtle. This allows the user to see a parse tree as it is being built and, as a side-effect, gives a better understanding of PROLOG's chronological backtracking.The research reported herein was supported by the Swedish Board for Technical Development (STU) and Atari Research, Cambridge, Massachusetts.