Ch 1: Scientific Understanding of Behavior Ch 4: Studying Behavior

The Scientific Method A scientific approach to knowledge is empirical rather than intuitive Empiricism is knowledge based on observations Data are collected that form the basis of conclusions Uses rules for collecting and evaluating data

Hypothesis A tentative explanation for something [Ch2, p17]; a testable statement: “Square chopsticks work better than round chopsticks” An operational definition describes the variables and techniques the researcher uses to measure or manipulate a variable. “ In transferring uncooked pennette pasta from one bowl to another, square chopsticks lead to better performance (i.e., more pasta transferred) than round chopsticks.”

Variable: any event, situation, or behavior that varies Situational variables describe characteristics of the environment. Response variables are the responses or behaviors of individuals. Participant or subject variables are individual differences. Mediating variables are psychological processes that mediate the effects of a situational variable on a particular response.

Which of the following is NOT a variable? A. Hair color B. Inches in a foot C. Weight D. Attitudes on gun control E. Intelligence scores

Which of the following is NOT a variable? A. Hair color B. Inches in a foot C. Weight D. Attitudes on gun control E. Intelligence scores Variable: any event, situation, or behavior that varies

Relationships Between Variables A correlation exists when there is a relationship or association among variables two different measures of the same people, events, or things vary together (covary)  How is chopstick shape correlated with transference of pasta?  Do square chopsticks and more pasta transferred go together?  How does proficiency with chopsticks correlate with pasta transference?

Experimental method Scientists manipulate one or more variables and observe the effects of this manipulation on behavior. Independent variables: The factors that the researcher controls or manipulates in order to determine their effect on behavior Dependent variables: The measures of behavior that are used to assess the effect (if any) of the independent variables

In an experiment… researchers typically wish to identify the causes of a phenomenon. Example:  Do square chopsticks cause the number of pasta pieces transferred to increase?  Does being rejected cause anxiety?

A causal inference may be made when there is… covariation of cause and effect, a time-order relationship (temporal precedence), and elimination of alternative explanations

An attempt to keep all extraneous variables constant Randomization ( random assignment ) Comparable groups are formed by assigning subjects randomly to conditions prior to implementing the independent variable Experimental control

Confounding occurs when two potentially effective independent variables are allowed to covary simultaneously. It is impossible to determine what variable is responsible for any obtained difference in performance. A confounding variable is an unexpected, uncontrolled variable, sometimes called the third-variable problem.

In applied research… psychologists conduct research in order to change people’s lives for the better. Applied research is conducted to address issues in which there are practical problems and potential solutions. Program evaluation

Basic research… seeks primarily to understand behavior and mental processes. asks questions about the nature of behavior - Theoretical issues concerning phenomena such as cognition, emotion, motivation, learning, psychobiology, personality development, and social behavior.

Applied or Basic Research? Chopsticks Challenge?

Test Yourself: Applied or Basic Research? 1) What are the predictors of teenage sexual behavior?

Test Yourself: Applied or Basic Research? 1) What are the predictors of teenage sexual behavior? BASIC

Test Yourself: Applied or Basic Research? 2) In what ways can video games increase aggression among children?

Test Yourself: Applied or Basic Research? 2) In what ways can video games increase aggression among children? APPLIED

Test Yourself: Applied or Basic Research? 3) How do neurons generate neurotransmitters?

Test Yourself: Applied or Basic Research? 3) How do neurons generate neurotransmitters? BASIC

Test Yourself: Applied or Basic Research? 4) Does memory process visual images and sound simultaneously?

Test Yourself: Applied or Basic Research? 4) Does memory process visual images and sound simultaneously? BASIC

Test Yourself: Applied or Basic Research? 5) How can peer groups influence romantic behavior?

Test Yourself: Applied or Basic Research? 5) How can peer groups influence romantic behavior? APPLIED

Test Yourself: Applied or Basic Research? 6) Which coping strategies are best for tsunami survivors?

Test Yourself: Applied or Basic Research? 6) Which coping strategies are best for tsunami survivors? APPLIED

Evaluating Research: Three Validities  Construct validity – the adequacy of the operational definitions  Internal validity – the ability to draw conclusions about causal relationships  External validity – the extent to which the results can be generalized to other populations and settings