PSYCHOLOGICAL RESEARCH METHODS AND STATISTICS

What is research?

Samples- relatively small group out of a whole population under study Must be representative of the population in

question Random sample- each individual has an

equal chance of being represented Stratified sample- deliberately pick

individuals who represent the various subgroups

Methods of Research

Naturalistic Observation Observe behavior in natural environment Avoid disturbing and stay inconspicuous

Case Studies Most are long-term observations with diaries, tests, and

interviews Very powerful research tool, but cannot prove or disprove

Surveys Most practical way to gather data on attitudes, beliefs, and

experiences of large numbers of people Can include questionnaires, interviews

Methods of Research

Longitudinal Studies Studies same group of people at regular interviews over a

period of years

Cross-Sectional Studies Randomly selected groups organized on basis of age Less expensive and time consuming than longitudinal

studies

Correlations and Explanation Want to examine relationship between two sets of

observations and how they relate Does not mean cause and effect

Experiments

Enables investigator to control the situation and decrease possible influences

Has hypothesis, variables, experimental group, control group

Can determine if independent variable influences behavior and how it does so

Final results do not constitute the final word on the subject Experiment must be replicated

Ethical Issues

Ethics- methods of conduct, or standards, for proper and responsible behavior

Psychologists are responsible for dignity and welfare of participants

Must obey all state and federal laws and professional standards

Rights must be agreed on for researchers and participants before starting

Ethical Issues

When obtaining consent, everyone must be fully informed

Deception is used only if no better alternative is available, must not interfere with willingness to participate

The welfare and confidentiality of all participants are to be protected

Problems and Solutions in Research Self-fulfilling prophecy- having

expectations about a behavior and then acting in some way to carry out that behavior Single-blind or double-blind techniques

used to avoid

Single-blind experiment- participants are “blind” about treatment given

Double-blind- both researchers and participants are “blind” about the treatment given

The Milgram Experiment

1960s Stanley Milgram Would participants administer painful

shocks to others because an authority figure’s instruction?

2,000 paid male volunteers “Learners” recited a memorized list Every mistake required volunteer to

deliver an electronic shock Each shock would increase in voltage

The Milgram Experiment

“Learners” pretended to be shocked, volunteers thought it was real

Although it seemed hard, 62% of volunteers delivered a full range of shock up to maximum voltage

Later, volunteers were told that no actual shocking took place

Was this single-blind or double-blind? Was this ethical?

The Placebo Effect

Placebo effect- a change in a participant's illness or behavior that results from a belief that the treatment will have an effect, rather than the actual treatment

1961 study-Experimental groups given “new drug”, control group given no drugs at all

After 6 weeks, 53-80% of experimental group noticed benefits

No group was given actual drugs during study