Chapter 2Chapter 2Understanding the Understanding the Research LiteratureResearch Literature

Searching the literatureSearching the literature

Bibliographic databasesBibliographic databases– ProquestProquest– ERICERIC– PsycINFO – produced by the APA and PsycINFO – produced by the APA and

widely used for searching psychological widely used for searching psychological literatureliterature

Searching the literatureSearching the literature

Peer reviewed journals – common layout:Peer reviewed journals – common layout:– Abstract – short summaryAbstract – short summary– IntroductionIntroduction– MethodsMethods– ResultsResults– DiscussionDiscussion

The literature also includes review The literature also includes review articles, books, chapters, edited books, articles, books, chapters, edited books, etc.etc.

Searching the literatureSearching the literature

Scientific research isScientific research is– Peer reviewed – process whereby the Peer reviewed – process whereby the

editor of a journal sends submitted editor of a journal sends submitted manuscripts out to be reviewed by other manuscripts out to be reviewed by other researchers in the same field of study.researchers in the same field of study.

– Reviewed blind – the reviewers are not Reviewed blind – the reviewers are not aware of the author of the article they aware of the author of the article they are reviewing and the author does not are reviewing and the author does not know who the reviewers are.know who the reviewers are.

This process helps to maintain a high This process helps to maintain a high standard of quality in research.standard of quality in research.

The research articleThe research article

The Abstract – comprehensive The Abstract – comprehensive summary summary of the article describing of the article describing what was done, what was done, to whom, and what to whom, and what was found.was found.

The Introduction – background on the The Introduction – background on the research problem.research problem.

IntroductionIntroduction• 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 The overall goal is to connect the current literature to your proposed purpose and designto your proposed purpose and design

– Introduce the problem/questionIntroduce the problem/question– Develop the background informationDevelop the background information

TheoryTheory Past MethodologyPast Methodology

– Statement of the rationale for the current study Statement of the rationale for the current study (final paragraph of intro)(final paragraph of intro)

PurposePurpose HypothesisHypothesis

The tone is technical and descriptive, not creative The tone is technical and descriptive, not creative or inflammatory. Avoid quotes and footnotesor inflammatory. Avoid quotes and footnotes

The research articleThe research article– Independent Variable(s) – the variable that is Independent Variable(s) – the variable that is

manipulated by the researcher.manipulated by the researcher. Participant variables – inherent in the participants Participant variables – inherent in the participants

(e.g.. gender)(e.g.. gender)

– Dependent Variable – response measure that Dependent Variable – response measure that we think will be influenced by the IV.we think will be influenced by the IV.

– Moderating Variables – influence the Moderating Variables – influence the relationship between the IV and DV.relationship between the IV and DV.

– Mediating Variables – variables that intervene Mediating Variables – variables that intervene between the IV and DV in their cause-between the IV and DV in their cause-

effect effect relationship.relationship.

The research articleThe research article

The Method Section – details about The Method Section – details about exactly how the variables were exactly how the variables were measured, manipulated, and measured, manipulated, and controlled.controlled.– Participants/Subjects – humans/animals Participants/Subjects – humans/animals

that that participated in the researchparticipated in the research

– Materials/Apparatus – details about Materials/Apparatus – details about equipment, tests, etc.equipment, tests, etc.

– Procedure – chronological sequence of Procedure – chronological sequence of what happened to the participants.what happened to the participants.

The research articleThe research article

The Results – statistical information The Results – statistical information about about whether or not the data whether or not the data support the support the research hypothesis.research hypothesis.

– In research statistics are used for two In research statistics are used for two purposes:purposes: To summarize dataTo summarize data

To test research hypothesesTo test research hypotheses

The research articleThe research article

– Descriptive statisticsDescriptive statistics – includes measures of – includes measures of central tendency, variability, and the central tendency, variability, and the

strength strength of the relationship between of the relationship between variables.variables. MeanMean ••RangeRange MedianMedian ••VarianceVariance ModeMode •• Standard deviation Standard deviation

– Pearson Product-Moment correlation - most Pearson Product-Moment correlation - most common measure of association common measure of association

(symbolized (symbolized as as rr). Describes how strongly ). Describes how strongly variables are variables are related to one another.related to one another.

Confidence intervalsConfidence intervals

Used when we are interested in Used when we are interested in estimating estimating population parameters.population parameters.

Report an interval within which we Report an interval within which we estimate the true population estimate the true population parameters to fall.parameters to fall.

The research articleThe research article

Inferential statisticsInferential statistics – used to – used to generalize the findings of a study to generalize the findings of a study to a whole population.a whole population.

– Common Tests of SignificanceCommon Tests of Significance – used in – used in hypothesis testing to determine whether hypothesis testing to determine whether results are statistically significant.results are statistically significant. t-t-testtest – used to compare means of two – used to compare means of two

groups.groups.

FF- test – - test – used to compare means of more used to compare means of more than two groups. (ANOVA, ANCOVA)than two groups. (ANOVA, ANCOVA)

Chi-square – used to compare frequencies.Chi-square – used to compare frequencies.

Basic tests of significanceBasic tests of significance

t-t-testtest – used to compare means of – used to compare means of two two groups.groups.

FF- test – - test – used to compare means of used to compare means of more more than two groups.than two groups.

Chi-square – used to compare Chi-square – used to compare frequencies.frequencies.

Effect size – provides some indication of the Effect size – provides some indication of the strength of the effect.strength of the effect.

Basic tests of significanceBasic tests of significance

Regression – use a predictor variable Regression – use a predictor variable to to predict a criterion variable.predict a criterion variable.

Multiple Regression – using more Multiple Regression – using more than than one predictor variable to one predictor variable to predict a predict a criterion variable.criterion variable.

The research articleThe research article The Discussion describes the outcome of describes the outcome of

the research in wordsthe research in words– Briefly summarize what you foundBriefly summarize what you found

Integrates the outcome of the study with Integrates the outcome of the study with previous research findingsprevious research findings– Here is how you data fit in to the larger literature Here is how you data fit in to the larger literature

basebase Draws conclusionsDraws conclusions

– Based on theory or practical applicationBased on theory or practical application May present suggestions for future researchMay present suggestions for future research

– LimitationsLimitations