Research Design

Experimental Method

Why do we conduct Psychological research? (demos first) Hindsight Bias

the “I-knew-it-all-along” phenomenon Ex:

Overconfidence we tend to think we know more than we

do Ex:

Why do research?

Experiment Understanding the cause and

effect relationship between two variables. Ex: From 40 studies ??

Scientific Method

• State Problem• Develop a

Hypothesis• Operationalize

Definitions• Identify Variables • Identify Population

& sample size

Hypothesis…

Hypothesis a testable

prediction

Example: If people watch violent television they will be more aggressive.

Variables….

Independent Variable the experimental factor that is

manipulated Ex- Watching Violent TV

Dependent Variable Measure of outcome of independent Ex-Aggression

Operationalize….

Operational Definition a statement of procedures used to

define research variables Ex: Watching Violent TV=

Aggression=

Forming Groups

• Experimental Group- Those exposed to the independent variable

• Ex: ?

• Control Group- Those not exposed to the independent variable.

• Ex: ?

Confounding Variables

• Defined: a difference between experimental and control conditions that may effect the dependent variable

-Subject-related=

- some subjects may self select

groups.

-Situation-related=

- location, time of day, weather, presence of others.

Common Flaws in Research

Population and samples.. Population- The total group of subjects available .• Ex:

• Representative Sample- - Do research subjects stand in for total population? Ex:My Ap Students

• Random Assignment of a sample assigning participants to groups by chance Why do we randomly assign?

Stratified Sample--sample represents the population based on a criteria.

( race, Gender. age) -Why stratify a sample?

Methods to overcome experimenter bias…

• Placebo &Placebo Effect-?

• Double-Blind Procedure- neither subjects nor researchers can affect outcome of experiment.

• Ex

APA Ethical Guidelines

• Informed Consent

• No Coercion

• Confidential Results

• No Risk or Harm

• Debrief

Advantages & Disadvantages: Experiment• Advantages:• CAN establish cause and effect• Can actively manipulate variables

via operationalization of variables• Can use double blind procedure• Can distinguish between real and

placebo effects• Can be replicated

Disadvantages:

• Experiments may be artificial or contrived

• Hard to establish controls, eliminate confounding variables

• Probability of bias

• $ and time consuming

Stop here…

Others Methods of Research:

• Case History= A biographical review of patients relevant history.

• Advantages:• - In depth info

- Rare Phenomena or unusual cases- Preexisting cases don’t involve ethics

- Time and $ Factors- Disadvantages:- Can’t generalize results

- Inaccurate reporting- no cause and effect

Description

Survey the self-reported attitudes or behaviors

of people representative, random sample of

people

Limitation:

Intentions are not always translated into action

Demo- The survey

• Wording of survey question• NY American Museum of Natural

History

( word ignorance)

CBS News Poll• (Gender and race influence)• 1992 Holocaust Survey• ( poor framed questions)

Naturalistic Observation:

Naturalistic Observation observing and recording behavior in

naturally occurring situations

• Advantages: natural setting

• Disadvantages: cant generalize, variables are not controlled