Chapter 4 Glossary

Psychological Abstracts: a useful resource that contains abstracts from a wide variety of journals. The Abstracts can be searched by year of publication, topic of article, or author. The electronic version of Psychological Abstracts is called PsycINFO. (p. 113)

abstract: a short, one-paragraph summary of a research proposal or article. The abstract should not be more than 120 words long. It comes before the introduction. (p. 113)

introduction: the part of the article that occurs right after the abstract. In the introduction, the authors tell you what their hypothesis is, why their hypothesis makes sense, how their study fits in with previous research, and why their study is worth doing. (p. 114)

method section: the part of the article immediately following the introduction. Whereas the introduction explains why the study was done, the method section describes what was done. For example, it will tell you what design was used, what the researchers said to the participants, what measures and equipment were used, how many participants were studied, and how they were selected. The method section could also be viewed as a "how we did it" section. The method section is often subdivided into three subsections: participants, apparatus, and procedure. (p. 119)

results section: the part of the article immediately following the method section that reports selected statistical results and relates those results to the hypotheses. From reading this section, you should know whether the results supported the hypothesis. (p. 121)

discussion: the part of the article immediately following the results section that interprets the results. For example, the discussion section may explain the importance of the findings and suggest research projects that could be done to follow up on the study. (p. 126)

direct (exact) replication: a later copy of the original study. Direct replications are useful for establishing that the findings of the original study are reliable. (p. 128)

systematic replication: a study that varies from the original study only in some minor aspect. For example, a systematic replication may use more participants, more standardized procedures, more levels of the independent variable, or a more realistic setting than the original study. (p. 131)

conceptual replication: a study that is based on the original study, but uses different methods to better assess the true relationships between the treatment and dependent variables. In a conceptual replication, you might use a different manipulation or a different measure. The conceptual replication is the most sophisticated kind of replication and usually is used to improve construct validity. (p. 137)

Type 1 error: when variables really are not related, concluding that the variables are related. Usually, if the results of a statistical test suggest that the relationship between variables observed in the sample is a reliable one, the test is right. However, tests can be fooled: Sometimes, observed relationship that is declared statistically significant is just due to a coincidence. Type 1 errors are also called  "false positives." (p. 129)

file drawer problem:  If there is no relationship between variables,  studies that find no relationship will just end up in file drawers, whereas the studies that "find" a relationship (the Type 1 errors) may get published.  (p. 130)

Type 2 error: when variables are really related, failing to detect that relationship; also called a false negative. Often, due to a lack of power (p.129)

power: the ability to detect real differences and find them statistically significant. Power can be increased by using sensitive measures to study  many participants in a highly controlled environment. (p. 116)