Methodological? Or Dialectical?: Reflections of Scientific Inquiry in Biology Textbooks

International Journal of Science and Mathematics Education - Given the importance of cultivating scientific literate societies, the integration of scientific inquiry into school curriculum is key...     

A Study of the Statistical Inference Criteria: Can We Agree on When to use Z Versus t?

Authors who write introductory business statistics texts do not agree on when to use a t distribution and when to use a Z distribution in both the construction of confidence intervals and the use of hypothesis testing. In a survey of textbooks written in the last 15 years, we found the decision rules to be contradictory and, at times, the explanations unclear. This paper is an attempt to clarify the decision rules and to recommend that one consistent rule be chosen to minimize confusion to students, instructors, and practitioners. Using the t distribution whenever σ is unknown, regardless of sample size, seems to provide the best solution both theoretically and practically.     

Analysis of a trial-spacing effect with relatively long intertrial intervals

In three experiments with rat subjects, we examined the effects of trial spacing in appetitive conditioning. Previous research in this preparation suggests that self-generated priming of the conditional stimulus (CS) and/or unconditional stimulus (US) in short-term memory is a cause of the trial-spacing effect that occurs with intertrial intervals (ITIs) of less than 240 sec. Experiment 1 nonetheless showed that a trial-spacing effect still occurs when ITIs are increased beyond 240 sec, and that the effect of ITI over 60–1,920 sec on conditioned responding is best described as a linear function. In Experiment 2, some subjects were removed from the context during the ITIs, preventing extinction of the context. Removal abolished the advantage of the long ITI, suggesting the importance of exposure to the context during the long ITI. Experiment 3 still produced a trial-spacing effect in a within-subjects design that controlled for the level of context conditioning and reinforcement rate in the absence of the CS. Overall, the results are most consistent with the idea that adding time to the ITI above 240 sec facilitates conditioning by extinguishing context-CS associations—and possibly context-US associations—that otherwise interfere with CS-US learning through retrieval-generated priming (see, e.g., Wagner, 1981).     

Creative Data in Business Statistics Courses

This paper discusses an innovative approach for using live data generated through student projects or through experiments using student subjects. This live data set, in which the students have a vested interest, becomes the foundation upon which the learning of the statistical concepts is built.