Basic Research Methodologies

Psych 231: Research Methods in Psychology

Announcements

Exam 1: Sept 17 (a week from Wednesday)

An example

Claim: People perform best with 8 hours of sleep a night.

How might we go about trying to test this claim? – How should we test it (what methods)? – What are the things (variables) of interest? – What is the hypothesized relationship between these

variables?

General research approaches Descriptive: Describe variables as they exist

– Observational – Survey – Case studies

Correlational - measures two (or more) variables in order to describe the relationship between them

Experimental: Systematic manipulation and observation of non-naturally occurring events

Observational methods

The researcher observes and systematically records the behavior of individuals

– Naturalistic observation

– Participant observation

– Contrived observation

Naturalistic observation

Observation and description of behaviors within a natural setting– It is generally used with naturally occurring and

ongoing phenomena with little experimenter intervention

Naturalistic Observation

Can be difficult to do well– A lot of work is often needed to develop coding

systems of behavioral categories– Need to be careful not to influence the behaviors

as a result of being observed

Naturalistic Observation

Can be difficult to do well Good for behaviors that don’t occur (as well)

in more controlled settings– Walking example

Naturalistic Observation

Can be difficult to do well Good for behaviors that don’t occur (as well)

in more controlled settings Often a first step in the research project

– helps to identify what some of the important variables are

– then the next step is to move into more controlled settings for further tests

Participant Observation The researcher engages in the same

behaviors as those being observed– May allow observation of behaviors not normally

accessible to outside observation– Internal perspective from direct participation

• But could lead to loss of objectivity

– Potential for contamination by observer

Contrived observation

The observer sets up the situation that is observed– Observations of one or more specific variables

made in a precisely defined setting– Much less global than naturalistic observations– Often takes less time

– However, since it isn’t a natural setting, the behavior may be changed

Observational methods

Advantages– may see patterns of behaviors that are very

complex and realized on in particular settings– often very useful when little is known about the

subject of study– may learn about something that never would have

thought of looking at in an experiment

Observational methods

Disadvantages– Causality is a problem– Threats to internal validity because of lack of

control• Every confound is a threat• Lots of alternative explanations

– Directionality of the relationship isn’t known– Sometimes the results are not reproducible

Survey methods Widely used methodology

– those annoying things in the mail and by phone– US Census

Can collect a lot of data– Lots of participants in a short amount of time– Can collect subjective information

Done correctly, can be a very difficult method– constructing good questions, rating scales, etc.

Doesn’t provide clear cause-effect patterns

Case Histories

Intensive study of a single person, a very traditional method – Get a very detailed description– Fits well with clinical work

Typically an interesting (and often rare) case– The man who mistook his wife for a hat– NA (fencing accident, amnesia)

Case Histories

This view has a number of disadvantages– There may be poor generalizabilty– There are typically a number of possible

confounds and alternative explanations

Correlational Methods

Measure two (or more) variables for each individual to see if the variables are related

Used for:– Predictions– Reliability and Validity– Evaluating theories

Problems: Can’t make casual claims

Causal claims

We’d like to say: – variable X causes variable Y

To be able to do this:– The causal variable must come first– There must be co-variation between the two

variables– Need to eliminate plausible alternative

explanations

Causal claims Directionality Problem:

– Airplanes and coffee spills– Happy people sleep well

• or is it that sleeping well when you’re happy?

Third variable problem:– Do Storks bring babies?

• A study reported a strong positive correlation between number of babies and stork sightings

Theory 1: Storks deliver babies

Theory 2: underlying third variable

The experimental method Manipulating and controlling variables in laboratory

experiments Must have a comparison

– At least two groups (often more) that get compared– One groups serves as a control for the other group

Variables– Independent variable - the variable that is manipulated – Dependent variable - the variable that is measured – Control variables - held constant for all participants in the

experiment

The experimental method

Advantages– Precise control possible– Precise measurement possible– Theory testing possible– Can make causal claims

The experimental method

Disadvantages– Artificial situations may restrict generalization to

“real world”– Complex behaviors may be difficult to measure

Next time

Ethics in research Read chapter 3