Experimental vs. Causal-Comparative

StudiesTopic 3

Experimental StudyStudy where treatments are given to observe

their effectsTreatments – input or stimulus given by the

researcher

Not useful when a study would be physically, ethically, legally, or financially impossible

DemographicsUsed to define groups in a study

People with similar background characteristics such as socioeconomic status

Causal-Comparison StudyNon-experimental study

Also called ex post facto study

Characteristics of the studyObserve and describe a current conditionLook to the past to identify possible causesNo treatment given

More potential pitfalls – need to select comparison groups carefully

Types of Nonexperimental

ResearchTopic 4

Nonexperimental Studies Purpose is to

observe/measure

Researcher does not try to change participants in any way

Causal-Comparative Research

Survey

Census

Case Study

Longitudinal Research

Correlational Research

Research Methods

Causal-Comparative Research

Look to the past for causes of a current condition

Interested in the causality, but an experiment is not possible

SurveyAlso known as a poll

Describes the attitudes, beliefs and behaviors of a population

Uses a sample or portion of the population being studied

With a good sample, generalizations about the population may be drawn

CensusJust like a survey, but all individuals in the

population participate instead of using a sample

Case StudyUsually only one participant

Often used in clinical psychology

Focus on thorough knowledge of an individual over a period of time

In-depth questioning occurs

Longitudinal ResearchA study over a long period of time to trace

developmental trends

Correlational ResearchResearchers study the degree of a relationship

of quantitative variables

Example: college admissions test and GPAs“Did those with high admissions scores tend to

earn high GPAs?”

Research MethodsQuantitative

Qualitative

Historical

Quantitative ResearchData is easy to quantify or put a number to

Allows for statistical analysis

Qualitative ResearchData is gathered through open-ended interviews

Analyzed through major and minor themes in responses

Uses semi-structured interviewsCore list of questionsDeviating follow-up questions

Historical ResearchTo understand the past

Use facts and dates to understand the dynamics of human history

Driven by theories and hypotheses

Hypotheses are evaluated using collected data

Both qualitative and quantitative methods are used

Will not be a focus of this text