Research Strategies: How Psychologists Ask and Answer Questions Module 3 Psychology 7e in Modules

Research Strategies: How Psychologists Ask and Answer Questions Description The Case Study The Survey Naturalistic Observation Correlation Correlation and Causation Illusory Correlation Perceiving Order in Random Events

Research Strategies: How Psychologists Ask and Answer Questions Experimentation Exploring Cause and Effect Evaluating Therapies Independent and Dependent Variables Statistical Reasoning Describing Data Making Inferences

Is language uniquely human? Descriptive Methods Case Study A technique in which one person is studied in depth to reveal underlying behavioral principles. Is language uniquely human? Advantage: tremendous amount of detail. Disadvantage: cannot apply to others. Famous case study: Phineas Gage OBJECTIVE 3-1| Identify the advantages and disadvantages of case studies in studying behavior and mental processes. Psychology 7e in Modules

Survey A technique for ascertaining the self-reported attitudes, opinions or behaviors of people usually by questioning a representative, random sample of people. OBJECTIVE 3-2| Identify the advantages and disadvantages of surveys in studying behavior and mental processes, and explain the importance of wording effects and random sampling. http://www.lynnefeatherstone.org Psychology 7e in Modules

Wording can change the results of a survey. Wording Effect Wording can change the results of a survey. Q: Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid)

False Consensus Effect Survey False Consensus Effect A tendency to overestimate the extent to which others share our beliefs and behaviors.

Survey Population – all the cases in a group Random Sampling From a population, if each member has an equal chance of inclusion into a sample, we call that a random sample (unbiased). The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.

Random Sampling from Population LO 1.9 Case studies and surveys INFERENCE POPULATION SAMPLE

Naturalistic and laboratory settings Descriptive Methods Naturalistic observation – watching animals or humans behave in their normal environment. Major Advantage: Realistic picture of behavior. Disadvantages: Observer effect - tendency of people or animals to behave differently from normal when they know they are being observed. Participant observation - a naturalistic observation in which the observer becomes a participant in the group being observed (to reduce observer effect).

Naturalistic and laboratory settings Descriptive Methods Laboratory observation – watching animals or humans behave in a laboratory setting. Advantages: Control over environment. Allows use of specialized equipment. Disadvantage: Artificial situation that may result in artificial behavior. Descriptive methods lead to the formation of testable hypotheses. Menu

(positive or negative) Correlation When one trait or behavior accompanies another, we say the two correlate. Indicates strength of relationship (0.00 to 1.00) Correlation coefficient r = + 0.37 OBJECTIVE 3-4| Describe positive and negative correlations and explain how correlational measures can aid the process of prediction. Correlation Coefficient is a statistical measure of relationship between two variables. Indicates direction of relationship (positive or negative) Psychology 7e in Modules

Finding Relationships Correlational technique Correlation coefficient ranges from 0 to 1.00 Closer to 1.00, the stronger the relationship between the variables. No correlation = 0.0. Perfect correlation = -1.00 OR +1.00. Positive correlation – variables are related in the same direction. As one increases, the other increases; as one decreases, the other decreases. Negative correlation – variables are related in opposite direction. As one increases, the other decreases. CORRELATION DOES NOT PROVE CAUSATION!!! Menu

Scatterplots Perfect positive correlation (+1.00) Scatterplot is a graph comprised of points generated by values of two variables.

Scatterplots Perfect negative correlation (-1.00) No relationship (0.00) Scatterplot on the left shows a negative correlation, and the one on the right shows no relationship between the two variables.

Data showing height and temperament in people.

Scatterplot Scatterplot showing relationship between height and temperament in people with a moderate positive correlation of +0.63.

LO 1.10 Correlational technique Menu

LO 1.10 Correlational technique Menu

Correlation and Causation OBJECTIVE 3-5| Explain why correlational research fails to provide evidence of cause-effect relationships. Psychology 7e in Modules

Correlation does NOT prove causation LO 1.10 Correlational technique Correlation does NOT prove causation Menu

Correlation Coefficient Interpretation Range Strength of Relationship 0.00 - 0.20 Very Low 0.20 - 0.40 Low 0.40 - 0.60 Moderate 0.60 - 0.80 High Moderate 0.80 - 0.90 High 0.90 - 1.00 Very High

Disconfirming evidence Illusory Correlation The perception of a relationship where none exists. Parents conceive children after adoption. Confirming evidence Disconfirming evidence Do not adopt Adopt Do not conceive Conceive OBJECTIVE 3-6| Describe how people form illusory correlations. Michael Newman Jr./ Photo Edit Psychology 7e in Modules

Order in Random Events Given large number of random outcomes, a few are likely to express order. Jerry Telfer/ San Francisco Chronicle OBJECTIVE 3-7| Explain the human tendency to perceive order in random events. Angelo and Maria Gallina won two California lottery games on the same day. Psychology 7e in Modules

Experimentation Exploring Cause and Effect The backbone of research in psychology. Experiments isolate causes and their effects. OBJECTIVE 3-8| Explain how experiments help researchers isolate cause and effect. Psychology 7e in Modules

Exploring Cause & Effect Many factors influence our behavior. Experiments (1) manipulate factors that interest us while keeping other factors under (2) control. Effects generated by manipulated factors isolate cause and effect relationships.

The Experiment Experimental approach and terms Operational definition - definition of a variable of interest that allows it to be directly measured. Independent variable (IV) - variable in an experiment that is manipulated by the experimenter. Dependent variable (DV) - variable in an experiment that represents the measurable response or behavior of the subjects in the experiment. Definition: Aggressive play IV: Violent TV DV: Aggressive play

For example, to study the effect of breast feeding on intelligence For example, to study the effect of breast feeding on intelligence. Breast feeding is the independent variable. OBJECTIVE 3-9| Explain the difference between an independent variable and a dependent variable. For example, the effect of breast feeding on intelligence - intelligence is the dependent variable. Psychology 7e in Modules

Double-blind Procedure Evaluating Therapies Double-blind Procedure In evaluating drug therapies it is important to keep the patients and experimenter’s assistants blind to which patients got real treatment and which placebo. OBJECTIVE 3-10| Explain why random assignment and double-blind procedure build confidence in research findings. Psychology 7e in Modules

Evaluating Therapies Random Assignment Assigning participants to experimental (Breast-fed) and control (formula-fed) conditions by random assignment minimizes pre-existing differences between the two groups. Sometime research participants out of enthusiasm or personal beliefs can affect the out come of an experiment. To control for such affects, a double-blind procedure is used, in which the participants and the experimenter’s assistants are not aware of which participants got real treatment and who got placebo. Psychology 7e in Modules

Random Assignment Experimental Group Test for Differences SAMPLE LO 1.11 Experimental approach and terms Experimental Group Test for Differences SAMPLE Control Group Menu Psychology 7e in Modules

Confounding Variables LO 1.11 Experimental approach and terms Effect of violent tv on aggression Experimental Group SAMPLE Are differences due to manipulation or confounding variable (mood)? Control Group Menu Psychology 7e in Modules

No Confounding Variables LO 1.11 Experimental approach and terms Effect of violent tv on aggression Experimental Group SAMPLE Differences due to manipulation, not an extraneous variable because mood randomly determined. Control Group Menu Psychology 7e in Modules

LO 1.11 Experimental approach and terms The Experiment Menu

A summary of steps during experimentation.

Below is a comparison of different research methods.