Chapter 4 – Research Methods in Clinical Psych Copyright © 2014 John Wiley & Sons, Inc. All...

Chapter 4 – Chapter 4 – Research Research Methods in Methods in Clinical PsychClinical Psych

Copyright © 2014 John Wiley & Sons, Inc. Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.All rights reserved.

Everyday Experience and Everyday Experience and ObservationObservation

Professional Experience and Professional Experience and ObservationObservation

Addressing Applied Problems Addressing Applied Problems and Needsand Needs

Previous ResearchPrevious Research TheoryTheory

Ways of Generating Ways of Generating Research HypothesesResearch Hypotheses


Correlation – the variables are Correlation – the variables are associated in some wayassociated in some way

Moderation – one variable Moderation – one variable influences the direction or size of influences the direction or size of anotheranother

Mediation - one variable explains Mediation - one variable explains the relationship between two the relationship between two othersothers

Relationships Between Relationships Between VariablesVariables


Institutional approvalInstitutional approval Informed consentInformed consent Inducements for participationInducements for participation Deception in researchDeception in research Debriefing Debriefing Humane care for animalsHumane care for animals Reporting resultsReporting results

Ethics in Research Ethics in Research (some principles)(some principles)


Internal validityInternal validity – controlling for biases – controlling for biases External validityExternal validity – how representative – how representative

and applicable the study isand applicable the study is Statistical conclusion validityStatistical conclusion validity – whether – whether

the study was designed in a way to the study was designed in a way to adequately test hypotheses through adequately test hypotheses through statistical methodsstatistical methods

StatisticalStatistical versus versus clinicalclinical significance significance– Effect sizeEffect size

Important Concepts to Important Concepts to Clinical ResearchClinical Research


Case StudyCase Study – detailed description of – detailed description of a case, which can allow for a great a case, which can allow for a great deal of hypothesis generatingdeal of hypothesis generating– Down side: many threats to internal Down side: many threats to internal

validity making it difficult to generalizevalidity making it difficult to generalize Single case designsSingle case designs A-B (two A-B (two

measures of symptoms pre and post measures of symptoms pre and post treatmenttreatment– A-B (designs with a number of clients)A-B (designs with a number of clients)– A-B-A (designs with one person at A-B-A (designs with one person at

different time points)different time points)

Clinical Research Clinical Research DesignsDesigns


Correlational designsCorrelational designs – association – association of variables (most common) of variables (most common) – Note even DSM group v control is a Note even DSM group v control is a

correlational design correlational design – ‘‘Median splitsMedian splits’ on a particular variable’ on a particular variable– Factor analysisFactor analysis – the underlying – the underlying

structure of a variablestructure of a variable– Mediator v Moderator designsMediator v Moderator designs– Structural equation modeling Structural equation modeling


Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

Quasi-experimental designsQuasi-experimental designs – – comparing groups when random comparing groups when random assignment is not available or assignment is not available or ethicalethical

Experimental DesignsExperimental Designs (the ‘gold (the ‘gold standard’ in clinical research) – standard’ in clinical research) – random assignment and random assignment and experimental manipulationexperimental manipulation– Randomized controlled trialsRandomized controlled trials (RCT) (RCT)



Meta-analysisMeta-analysis – summarizing – summarizing several similar studies through a several similar studies through a statistical analysisstatistical analysis– Effect sizeEffect size – a statistical measure of – a statistical measure of

how strong the experimental effect is how strong the experimental effect is (i.e., statistical significance does not (i.e., statistical significance does not say how strong the effect is, only that say how strong the effect is, only that it is unlikely to have randomly it is unlikely to have randomly occurred) occurred)



Importance of selecting a Importance of selecting a representative samplerepresentative sample (age, (age, gender, SES, ethnicity, etc.)gender, SES, ethnicity, etc.)

Sampling strategySampling strategy – how – how participants are chosen/recruitedparticipants are chosen/recruited– Probability samplingProbability sampling – requesting – requesting

participants from say, every 10participants from say, every 10thth person in a neighborhoodperson in a neighborhood

– Non-probability samplingNon-probability sampling – recruiting – recruiting through a method that will reach as through a method that will reach as many people as possible many people as possible

Selecting the Selecting the Participants Participants


Setting the sample sizeSetting the sample size – making – making sure there are enough participants sure there are enough participants to detect differences in groupsto detect differences in groups– Low powerLow power– Sufficient sample sizeSufficient sample size– Statistical significanceStatistical significance– Clinical significance Clinical significance

Selecting the Selecting the Participants Participants


Self-Report MeasuresSelf-Report Measures – – participant report.participant report.

Informant-Report MeasuresInformant-Report Measures – – report by someone who knows the report by someone who knows the participantparticipant

Rater EvaluationsRater Evaluations – – research research assistant rates the participantassistant rates the participant

Performance MeasuresPerformance Measures – – how a how a participant does on a task (e.g., participant does on a task (e.g., reaction time or behavioral reaction time or behavioral measure)measure)

Selecting the Selecting the Measures Measures


Projective MeasuresProjective Measures – – participant participant responses to ambiguous stimuli, which may responses to ambiguous stimuli, which may reflect the internal state of the participantreflect the internal state of the participant

Observation of BehaviorObservation of Behavior - - coding coding systems used to summarize complicated systems used to summarize complicated behavior behavior

Psychophysiological MeasuresPsychophysiological Measures – – a a range of measures reflecting biological range of measures reflecting biological markers (e.g., heart rate, blood pressure, markers (e.g., heart rate, blood pressure, neural activity)neural activity)

Archival DataArchival Data – – Data stored for some Data stored for some other purpose used for research (e.g., other purpose used for research (e.g., police records, health care utilization police records, health care utilization records, and academic records)records, and academic records)

Selecting the Selecting the Measures Measures


ReliabilityReliability Internal Consistency: Internal Consistency: How homogeneous the How homogeneous the

test items aretest items are Test-Retest Reliability: Test-Retest Reliability: How stabile over time How stabile over time

scores on a measure arescores on a measure are Inter-Rater Reliability: Inter-Rater Reliability: The consistency of The consistency of

scores on a measure across different raters or scores on a measure across different raters or observers.observers.

ValidityValidity Content Validity: Content Validity: How fully and accurately the How fully and accurately the

measure represents the construct being measure represents the construct being assessedassessed

Face Validity: Face Validity: How much the measure overtly How much the measure overtly appears to be measuring the construct of appears to be measuring the construct of interest.interest.

Psychometric Psychometric Properties of the Properties of the Measures Measures


Validity (cont.)Validity (cont.) Criterion Validity: Criterion Validity: The association of a The association of a

measure with a related criterionmeasure with a related criterion Concurrent Validity: Concurrent Validity: The association The association

of a measure with other relevant data of a measure with other relevant data measured at the same point in time.measured at the same point in time.– Predictive Validity: Predictive Validity: The association The association

of a measure with other relevant data of a measure with other relevant data measured at some future point in measured at some future point in time.time.



Validity (cont.)Validity (cont.) Convergent Validity: Convergent Validity: The association The association

between a measure and either other between a measure and either other measures of the same construct or measures of the same construct or conceptually related constructsconceptually related constructs

Discriminant Validity: Discriminant Validity: The association The association between measures that, conceptually, between measures that, conceptually, should not be relatedshould not be related

Incremental Validity: Incremental Validity: The extent to The extent to which a measure adds to the prediction which a measure adds to the prediction of a criterion beyond what can be of a criterion beyond what can be predicted with other measurement datapredicted with other measurement data



Chapter 4 – Research Methods in Clinical Psych Copyright © 2014 John Wiley & Sons, Inc. All...

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