Research Methods

Chapter 4Abnormal Psychology

Researching Abnormal Behavior

Scientific method

Developing a hypothesis

Research design

Research Methods

Case study

Correlation

Controlled experiment

Case Study

In depth study of a single person

Case studies in the history of psychology

Benefits and drawbacks to the case study method?

Withdrawal Designs

Getting a baseline

Gradually removing/reducing treatment

Notable behavior/symptom changes? May happen naturally over the course

of treatment

Correlational Method

Measures the degree and strength of a relationship

Are the variables linked/related?

Is there a link between social support and recovery from depression?

Is there a link between stress and mental illness?

Correlational Method

Positive correlation: both variables increase or both variables decrease

Negative Correlation: an increase in one variable is associated with a decrease in another variable

Correlational Design

Correlational designs measure the strength of a relationship

Are the variables strongly related?

Strongest positive correlation value= 1.0 Strongest negative correlation value= -

1.0

Correlational Designs

Epidemiological Research Prevalence: the number of people

with the disorder at any given time

Incidence: estimated number of new cases during a specific period of time

Helps to determine historical influences, reactions to interventions, etc.

Controlled Experiment Experimental Group: receives the

treatment

Control Group: no treatment

The experimental and control groups only differ in regard to the independent variable

Randomization- to reduce systemic bias

Controlled Experiment Independent variable: the variable

we manipulate/change

Dependent variable: the variable we measure

Experimental Method Single-blind procedure: participant

doesn’t know if he/she is receiving drug or placebo

Double-blind procedure: participant and researcher do not know if the participant receives drug or placebo

Experimental Method

Placebo effect: participants feel better after taking a sugar pill (which they think is a drug) because they expect to feel better

Comparative Treatment Groups

Comparing treatments across multiple groups

Comparable groups- to assess the effectiveness of different interventions

Internal Validity

Internal Validity: making sure nothing but the independent variable can influence the outcome

High internal validity- when the study is carefully controlled

External Validity

External Validity: findings can generalize to real-life settings

Psychological realism: extent to which psychological processes triggered in an experiment resemble real life psychological processes

External and Internal Validity: often a trade-off

Genetic Studies

Family studies

Adoption studies

Twin studies

Study Design Cross-sectional: comparing

different “cohorts” or age groups

Longitudinal: following the same group over time

Sequential: combines cross-sectional and longitudinal

Generalizability and Replication

Do the findings generalize to diverse groups?

When replicated, do the results hold?

Use of meta-analyses: combining the results of many studies on the same topic

Cross-Cultural and Cultural Research Are psychological disorders

universal or culture-specific?

Diversity in symptom patterns Depression: US- loss of interest; China-

worthlessness and suicidality

Cross-cultural research vs. cultural research

Ethical Issues

Principle: Do No Harm

Informed consent

Use of deception

Debriefing