A look at psychological research

General principles The concern for precise measurement Operational definitions – definitions which specify the procedure used to measure something Also, a way to give a study’s focus of concern a numerical value How do you measure anger, love, intelligence? Fun way to start Anecdotes, stories

Research designs Naturalistic observations ◦ A careful examination of an individual’s or animal’s behavior in more or less natural conditions No manipulation, just observation Often the first step in generating hypothesis’

Case histories A thorough description of a person or small group of people with unusual or noteworthy qualities Another source of hypothesis’ Just a super-sized anecdote ?

surveys A study of the prevalence of certain beliefs, behaviors, or attitudes based upon people’s responses to specific questions Many problems: sampling nonchalance the questions bias

Sample Social Survey 1. Are you involved in any kind of social activity? a) yes b) No c) Somewhat 2. Do you agree that you are well informed about the happenings around you and also current affairs? a) Strongly agree b) Agree c) Somewhat agree d) Disagree 3. On an average how much do you spend daily in reading the newspaper or watching television? a) More than one hour b) Less than one hour 4. Do you interact with outsiders a lot? a) yes b) No c) Sometimes 5. Have you ever taken part in any lawful public demonstration? a) yes b) No 6. Have you even been caught in any illegal activity? a) Yes( Please provide details) b) No

correlations A measure of the relationship between two variables Variable – a measurable item that can vary in magnitude Correlational study – a procedure in which the investigator measures the relationship between two variables without controlling either one

Correlations examples Between class attendance and final grade Between hours worked and $ earned Between smiles given and smiles received Between miles run/week and 5k time Between hours on internet and final grade Between exercise sessions and weight Between hair color and grade point average

Correlations graphic examples

The correlation coefficient R = the mathematical relationship between two variables, ranging from -1 to 1 Positive correlations approach 1 Negative correlations approach -1 A R of 0 means that there is no relationship between the two variables Look to R ’s absolute value when assessing its strength

Illusory correlations An apparent relationship based upon casual observations of unrelated or weakly related events Do people really get wild under a full moon? Does the weather affect arthritis symptoms?

Correlations and causation No matter how it might seem, correlations do not tell us about cause and effect We never really know if changes in one variable affects the other, or If a third, lurking, variable controls them both. Correlations help us predict but not explain or control behavior or experience.

experiments Milgram Experiment

experiments A study in which the investigator manipulates at least one variable while measuring at least one other variable By adjusting one variable or factor, while keeping all other factors constant, we can determine if that factor causes changes in the other(s)

More definitions: variables Independent variable – the variable which is manipulated, or adjusted, by the investigator Dependent variable – the variable which is measured by the investigator to determine the effects of the independent variable

groups Experimental group – receives the treatment (independent variable) that the experiment was designed to test Control group – handled exactly the same as the experimental group except for the independent variable Control groups usually receive a placebo

Hazards to be prepared for Biased groups To make sure that the experimental and control groups are as similar as possible, before being introduced to the independent variable we use random assignment Every participant must have an equal chance of being placed in either the experimental or the control group

more hazards Even unconsciously, investigators want to see their hypothesis confirmed and unintentionally might distort the results Placebo effect Also, the experiment’s participants might try to help prove the hypothesis Solution – Double blind – a procedure in which both the observer and the participant are unaware of which participants received which treatment and the experiment’s goals

review Hypothesis Select Method & Operational Definition Random Assignment of groups Run experiment (double blind) Collect and analyze results (data) Peer review Replication Ethics