Chapter 2 Understanding the Research Literature

Searching the literature Bibliographic databases Bibliographic databases –Proquest –ERIC –PsycINFO – produced by the APA and widely used for searching psychological literature

Searching the literature Peer reviewed journals – common layout: Peer reviewed journals – common layout: –Abstract – short summary –Introduction –Methods –Results –Discussion The literature also includes review articles, books, chapters, edited books, etc. The literature also includes review articles, books, chapters, edited books, etc.

Searching the literature Scientific research is Scientific research is –Peer reviewed – process whereby the editor of a journal sends submitted manuscripts out to be reviewed by other researchers in the same field of study. –Reviewed blind – the reviewers are not aware of the author of the article they are reviewing and the author does not know who the reviewers are. This process helps to maintain a high standard of quality in research. This process helps to maintain a high standard of quality in research.

The research article The Abstract – comprehensive summary of the article describing what was done, to whom, and what was found. The Abstract – comprehensive summary of the article describing what was done, to whom, and what was found. The Introduction – background on the research problem. The Introduction – background on the research problem.

Introduction Like a funnel – Broad at the top narrow at the endLike a funnel – Broad at the top narrow at the end The overall goal is to connect the current literature to your proposed purpose and designThe overall goal is to connect the current literature to your proposed purpose and design –Introduce the problem/question –Develop the background information  Theory  Past Methodology –Statement of the rationale for the current study (final paragraph of intro)  Purpose  Hypothesis The tone is technical and descriptive, not creative or inflammatory. Avoid quotes and footnotes The tone is technical and descriptive, not creative or inflammatory. Avoid quotes and footnotes

The research article –Independent Variable(s) – the variable that is manipulated by the researcher.  Participant variables – inherent in the participants (e.g.. gender) –Dependent Variable – response measure that we think will be influenced by the IV. –Moderating Variables – influence the relationship between the IV and DV. –Mediating Variables – variables that intervene between the IV and DV in their cause-effect relationship.

The research article The Method Section – details about exactly how the variables were measured, manipulated, and controlled. The Method Section – details about exactly how the variables were measured, manipulated, and controlled. –Participants/Subjects – humans/animals that participated in the research –Materials/Apparatus – details about equipment, tests, etc. –Procedure – chronological sequence of what happened to the participants.

The research article The Results – statistical information about whether or not the data support the research hypothesis. The Results – statistical information about whether or not the data support the research hypothesis. –In research statistics are used for two purposes:  To summarize data  To test research hypotheses

The research article –Descriptive statistics – includes measures of central tendency, variability, and the strength of the relationship between variables.  Mean Range  Median Variance  Mode Standard deviation –Pearson Product-Moment correlation - most common measure of association (symbolized as r). Describes how strongly variables are related to one another.

Confidence intervals Used when we are interested in estimating population parameters. Used when we are interested in estimating population parameters. Report an interval within which we estimate the true population parameters to fall. Report an interval within which we estimate the true population parameters to fall.

The research article Inferential statistics – used to generalize the findings of a study to a whole population. Inferential statistics – used to generalize the findings of a study to a whole population. –Common Tests of Significance – used in hypothesis testing to determine whether results are statistically significant.  t-test – used to compare means of two groups.  F- test – used to compare means of more than two groups. (ANOVA, ANCOVA)  Chi-square – used to compare frequencies.

Basic tests of significance t-test – used to compare means of two groups. t-test – used to compare means of two groups. F- test – used to compare means of more than two groups. F- test – used to compare means of more than two groups. Chi-square – used to compare frequencies. Chi-square – used to compare frequencies. Effect size – provides some indication of the strength of the effect. Effect size – provides some indication of the strength of the effect.

Basic tests of significance Regression – use a predictor variable to predict a criterion variable. Regression – use a predictor variable to predict a criterion variable. Multiple Regression – using more than one predictor variable to predict a criterion variable. Multiple Regression – using more than one predictor variable to predict a criterion variable.

The research article describes the outcome of the research in words The Discussion describes the outcome of the research in words –Briefly summarize what you found Integrates the outcome of the study with previous research findings Integrates the outcome of the study with previous research findings –Here is how you data fit in to the larger literature base Draws conclusions Draws conclusions –Based on theory or practical application May present suggestions for future research May present suggestions for future research –Limitations