Research Psychology PSYC 2618 Lecture 1B

A definition of contemporary psychology The scientific study of behavior and mental processes

Goal of psychology

Sources of knowledge Authority Logical reasoning Careful observation Intuition

Step 1: Choose a cup

Step 2: An empty un-chosen cup is removed

Optional Step 3: Switch choice to the remaining cup

Weaknesses of intuition Poor statistical reasoning Perceiving order in random events Hindsight bias

Hindsight bias The tendency to believe, after learning an outcome, that one could have foreseen it

Weaknesses of intuition (cont’d) Assuming that correlation proves causation

Correlation A measure of the extent to which two factors vary together

Strengths of the scientific method Ideas that can be confirmed or disconfirmed Replication

Replication repeating an earlier research study with different participants

Strengths of the scientific method (cont’d) Peer review

Research methods Case study

Case study studying a single person in great depth

Research methods (cont’d) Naturalistic observation Survey

Representative sample one that shows, in equivalent proportions, the relevant variables that characterize the population as a whole

Random sampling selecting your sample in a manner that guarantees each member of the population an equal chance of participating in the study helps ensure that the sample is representative

Research methods (cont’d) Experimentation

Experimentation Manipulating one or more independent variables to observe the effect on one or more dependent variables The most reliable method for determining cause-and-effect

Independent variable the suspected cause; the variable that is manipulated by the researcher

Dependent variable the suspected effect or outcome

Experimental group those subjects who receive some special treatment in regard to the independent variable

Control group those subjects who do NOT receive that special treatment Subjects are randomly assigned to groups.

Placebo Inactive substance or pseudotreatment

“Blind” subject One who does not know which experimental treatment, if any, they are receiving

Double-blind procedure A procedure in which subjects and research staff are ignorant about who has received the treatment or placebo