An Educational Tool for Formal Relational Database Query Languages

This article describes an educational tool, implemented in Prolog, that takes advantage of the connection between logic programming and databases to provide an evaluator for relational query languages. The tool utilizes a common data definition facility and provides the student with a choice of query languages: relational algebra, domain relational calculus, tuple relational calculus, and SQL. The students use the relational interpreter for a sequence of homework assignments that both provide invaluable feedback on each language and illustrate the differences between the languages.     

Portrayal of the History of the Photoelectric Effect in Laboratory Instructions

The literature on the pedagogical aspects of the photoelectric effect as used in the undergraduate student laboratory shows that little research has been done in this area. Our current study is an analysis of the instructions in 38, electronically published laboratory manuals for the photoelectric effect. The analyses were based on history and philosophy of science criteria that we had developed for evaluating the presentation of the photoelectric effect in introductory, university-physics textbooks. The results show that writers of laboratory instructions do not pay sufficient attention to the relevant background for the photoelectric effect. In our study, none of the instructions achieved a score of excellent, only 5% were scored as satisfactory, and only 7% mentioned the various aspects contained in our criteria. These results for our analysis of laboratory instructions are significantly less favorable than those achieved for physics textbooks in our previous study. Based on our work, we recommend that several historical aspects be included in all laboratory instructions for the photoelectric effect.