Psychological Research Methods Excavating Human Behaviors

***Hindsight Bias The tendency to believe, after learning the outcome, that you knew it all along. Only after Kerry won the Iowa Primary, did people begin to say that Dean was too liberal. What would people say about Kerry if Dean won?

Overconfidence We tend to think we know more than we do. 82% of U.S. drivers consider themselves to be in the top 30% of their group in terms of safety 81% of new business owners felt they had an excellent chance of their businesses succeeding. When asked about the success of their peers, the answer was only 39%. (Now that's overconfidence!!!)

Scientific Method Observe some aspect of the universe. Invent a theory that is consistent with what you have observed. Use the theory to make predictions. Test those predictions by experiments or further observations. Modify the theory in the light of your results. Go to step 3.

***Hypothesis A testable prediction, often implied by a theory ***Theory: an explanation using an integrated set of principles that organizes observations and predicts behaviors or events

Types of Research Descriptive Correlational Experimental

Descriptive Research Any research that observes and records. What is going on in this picture? We cannot say exactly, but we can describe what we see. Thus we have….. Descriptive Research Any research that observes and records. Does not talk about relationships, it just describes.

Types of Descriptive Research The Case Study The Survey Naturalistic Observation

***Case Study An observation where one person (or situation) is observed in depth. ***Replication: repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances ***Operational definition: used to define research variables For example: Human intelligence may be operationally defined as what an intelligence test measures

***Survey Done by choosing a random sample of a group and questioning them to obtain self-reported attitudes or behaviors Example: Your workplace conditions are made safe and comfortable at all times. 5 4 3 2 1 Choose how important this subject is to you, 5 being the most important.

***Random Sample If I ask you to do a study about the marbles in the big jar, you may randomly dump some of them in the smaller jar to make your life easier upon calculations in your experiment. Definition: a sample that fairly represents a population because each number has an equal chance of inclusion Members are the red marbles and the blue marbles

Why do we sample? One reason is the False Consensus Effect: the tendency to overestimate the extent to which others share our beliefs and behaviors. ***Population: all the cases in a group being studied

Survey Method: The Bad Low Response Rate People Lie or just misinterpret themselves. Wording Effects- some people don’t understand what you are asking but they will answer anyway How accurate would a survey be about the frequency of diarrhea?

Naturalistic Observation Observing and recording behavior in natural environment. No control- just an observer.

***Correlational A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other Does NOT say that one variable causes another. THIS IS NOT CAUSE AND EFFECT

Measured using a correlation coefficient. A statistical measure of the extent to which two factors relate to one another. Ranges from -1 to +1

How to Read a Correlation Coefficient

For positive correlations, both variables must be moving in the same direction, and vice versa for negative correlations. Correlations can only be perfect if the points NEVER deviate from the line. Sometimes positive correlations can be referred to as “direct” correlations and negative correlations can be referred to as “inverse” correlations

Experimental Research Explores cause and effect relationships. Constipation Eating too many bananas causes

Steps in Designing an Experiment Hypothesis Pick Population: Random Selection then Random Assignment. Operationalize the Variables Identify Independent and Dependent Variables. Look for Extraneous Variables Type of Experiment: Blind, Double Blind etc.. Gather Data Analyze Results

Experimental Vocabulary Independent Variable: factor that is manipulated Dependent Variable: factor that is measured Extraneous Variables: factors that effect DV, that are not IV. Experimental Group: Group exposed to IV Control Group: Group not exposed to IV Placebo: inert substance that is in place of IV in Control Group

Analyze Results Use measures of central tendency (mean, median and mode). Use measures of variation (range and standard deviation).

A Skewed Distribution Are the results positively or negatively skewed?