Sample and Population Diagram - A Teaching Tool

This article describes a simple, yet effective way to introduce and also review the concepts of ‘sample’ and ‘population’ using a Sample and Population Diagram.     

Conducting tests of hypotheses: The need for an adequate sample size

This article addresses the importance of obtaining a sample of an adequate size for the purpose of testing hypotheses. The logic underlying the requirement for a minimum sample size for hypothesis testing is discussed, as well as the criteria for determining it. Implications for researchers working with convenient samples of a fixed size are also considered, and suggestions are given about the steps that should be taken when they are not able to obtain a large enough sample. Finally, the implications of not having an adequate sample size for hypothesis testing are discussed to highlight the importance of determining sample size prior to conducting one’s study.     

Replacement of event-generated memories of nonreinforcement with signal-generated memories of reinforcement during partial reinforcement training: Effect on resistance to extinction

Event-generated memory refers to the memory of a reinforcement (R) or nonreinforcement (N) event from an immediately preceding trial;signal-generated memory refers to the memory of a temporally remote R or N, retrieval of which is generated by presentation of a signal with which the memory is associated (Haggbloom, 1988). In each of three experiments, Group Signal-R received runway discrimination training in Phase 1 to establish a stimulus as a signal for R, and partial reinforcement training in Phase 2. An extinction test measured learning about the memory of nonreward (S^N)—learning that occurs when S^N is retrieved on R trials that follow N trials. In Group Signal-H, those R trials were accompanied by the signal for R, a treatment we hypothesized would generate retrieval of the memory of reinforcement (S^R) so that signal-generated S^R would replace event-generated S^N as the operative memory, thereby eliminating the increased resistance to extinction normally produced by PRF training. In each experiment, Group Signal-R was less resistant to extinction than was a control group conditioned to respond to-event-generated S^N. Extinction was as rapid in Group Signal-R as it was in a consistent reinforcement control group (Experiment 1) and in a group given intertrial reinforcements to interfere with learning about S^N (Experiment 3). Experiment 2 tested two alternative interpretations of the failure to learn about S^N in Group Signal-R. Those alternatives were found to be less viable than the hypothesis that the signal for R actively recruited retrieval of a competing memory.     

Type of Positive Interdependence and Affiliation Motive in an Asynchronous, Collaborative Learning Environment

In this study, we investigated the effect of type of positive interdependence (roles, rewards, roles-plus-rewards, or no structure) and affiliation motives (high vs. low) in an asynchronous, collaborative learning environment. College reentry students worked together in small, fully online discussion groups that lasted for seven days. Results indicated that participants in groups given roles plus rewards interacted with their teammates significantly more than those given rewards only or no-structured-interdependence conditions. A significant positive correlation suggested that participants with higher numbers of interactions attained higher posttest scores. However, no significant differences were found in achievement by type of interdependence or by affiliation motive. Results also revealed that type of interdependence and affiliation motive had a significant impact on student attitudes. Implications for integrating small group work in online higher education settings are discussed.     

‘I like being a lab Rat’: student experiences of research participation

Undergraduate students are often expected to be participants in academic research. However, decisions relating to student participation in research are typically based on speculation or educator assumptions rather than a solid research base. We conducted three studies to investigate student experiences of research participation. These included online surveys (Study 1), semi-structured interviews (Study 2), and analysis of reflective essays (Study 3). A range of pedagogic and ethical issues were considered including motivation to participate, distress, and the educational value of participation. Findings suggest that the experience provides students with important opportunities to learn about research methodology and ethical issues which inform their own research practice. Further, students cite additional non-academic benefits of research participation such as self-discovery and networking opportunities. Negative experiences typically consisted of nervousness prior to the first laboratory study or boredom, though for some students (e.g. those uncomfortable in social situations) engagement in research may lead to anxiety. We conclude that participation in research has pedagogic value to students, and educators should promote those elements of the research experience (e.g. critiquing studies, networking with researchers) that are most beneficial. However, researchers and educators should also actively work to reduce apprehension and minimise potential distress.     

Does it pay to attend an elite private college? Evidence on the effects of undergraduate college quality on graduate school attendance

Much attention has recently focused on the rapidly rising costs of a college education, and whether the benefits of attending an elite private college have kept pace with the increasing costs. In this paper we analyze whether undergraduate college quality affects the likelihood that an individual attends graduate school. Using data on three cohorts of students from the National Longitudinal Study of the High School Class of 1972 and High School and Beyond, we find that on balance attendance at an elite private college significantly increases the probability of attending graduate school, and more specifically, graduate school at a major research institution.     

An empirical test of a taxonomy of responses to anomalous data in science

The purpose of this study was to test a taxonomy of seven proposed responses to anomalous data. Our results generally supported the taxonomy but indicated that one additional type of response should be added to the taxonomy. We conclude that there are eight possible responses to anomalous data: (a) ignoring the data, (b) rejecting the data, (c) professing uncertainty about the validity of the data, (d) excluding the data from the domain of the current theory, (e) holding the data in abeyance, (f) reinterpreting the data, (g) accepting the data and making peripheral changes to the current theory, and (h) accepting the data and changing theories. We suggest that this taxonomy could help science teachers in two ways. First, science teachers could use the taxonomy to try to anticipate how students might react to anomalous data so as to make theory change more likely. Second, science teachers could use the taxonomy as a framework to guide classroom discussion about the nature of scientific rationality. In addition, the taxonomy suggests directions for future research. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 623–654, 1998.     

Mexican American and European American College Students' Beliefs About Causes,Cures, and Sources of Help for Anxiety

Mexican American and European American college students rated an empirically derived list of the causes, cures, and sources of help for anxiety. Main effects were obtained for ethnicity on ratings related to cures and one source of help for anxiety. There were also significant differences in ratings of cause and cure beliefs for anxiety between men and women. Level of acculturation, however, was not found to be related to ratings among the Mexican American participants.