Psychology Unit II: Research Methods

RESEARCH METHODS

Hindsight Bias

• tendency to believe, after learning the outcome, that you knew it all along.

Overconfidence

• we tend to think we know more than we do.

Barnum Effect

• tendency for people to accept very general or vague characteristics of themselves and take them to be accurate.

Applied Research

• clear and practical
• you can use it

Basic Research

• explores questions that you may be curious about, but not intended to be immediately used.

Hypothesis

• expresses a relationship between two variables
• If, then statement

Ex. If a prisoner learns a work skill while in jail, then he is less likely to commit a crime when he is released. 

Variable

• that can vary among participants in a study

Independent Variable

• what is being manipulated in an experiment

Ex. administration of a drug - the dosage and the timing

Dependent Variable

• what is being measured in an experiment.

Ex. impact of the drug

Operational Definitions

• explain what you mean in your hypothesis 
• how will the variables be measured in "real life" terms?

Sampling

• identify population you want to study
• must be representative of the population you want to study

Experimental Method

• looking to prove casual relationships
• a cause has an effect

Ex. Smoking causes health issues.

Confounding Variable

• anything that could cause a change in B, that is not A.

Ex. weather can cause an increase or decrease in sales of ice cream and amount of murders.

Hawthorne Effect

• even control group may experience changes 
• the fact that you know you are in an experiment can cause change

Correlation Method

• expresses a relationship between two variables that does not show causation

Ex.  Height and weight: taller people tend to be heavier

Positive Correlation

• variable goes in the same direction

Ex. The more time you spend running on a treadmill, the more calories you will burn.

Negative Correlation

• Variables go in opposite directions

Ex. The more one works, the less free time one has.

Survey Method

• most common type of study in Psychology
• need a good random sample
• cheap and fast
• measures correlation

Naturalistic Observation

• watch subjects in natural environment
• do not manipulate environment

Correlation Coefficient

• number that measures the strength of a relationship
• range: -1 to +1 
• relationship gets weaker the closer you get to zero

Case Study

• detailed picture of one or a few subjects
• tells a story (descriptive research)
• does not give correlation data

Statistics

• recording the results from our studies

Descriptive Statistics

• describes sets of data

Range

• difference between the lowest and highest number

Standard Deviation

• variance of scores
• around the mean
• the higher the variance or standard deviation, the more spread out the distribution is

Z Scores

• a unit that measures the distance of one score from the mean
• positive z score means a number above the mean
• negative z score means a number below the mean

Human Research

• no coercion- must be voluntary
• informed consent
• anonymity
• no significant risk
• must debrief

Animal Research

• clear purpose 
• acquire animals legally
• treated in a humane way
• least amount of suffering possible