Unit 2

Hindsight Bias

• The tendency to believe after learning an outcome, that one would have foreseen it.
  
  

Overconfidence

• Our confidence in our knowledge is greater than our objective accuracy.
  
  

Critical Thinking

• Thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.
  
  

Hypothesis

• A testable prediction often implied by a theory.
  
  

  • Alternate: A statement of difference.
    
    

  • Null: A statement of no difference.
    
    

Theory

• An explanation using an integrated set of principles that organizes observations and predicts behaviors and events.
  
  

Operational Definitions

• A statement to describe the procedures used to define/measure the research variables (DV and IV) of a study.
  
  

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.
  
  

Naturalistic Observation

• Systematic observation of an organism in a natural setting.
  
  

Case Study

• In-depth study of one person or a small group of subjects.
  
  

Survey

• Method of collecting self-reported attitudes, opinions, or behaviors of people usually by questioning a representative, random sample of people.
  
  

Wording Effect

• The effects of subtle changes in the words, or the order of the words, change how people report their answer.
  
  

Sampling Bias

• The collection of samples that do not accurately represent the entire group.
  
  

Population

• All the cases in a group being studied, from which samples may be drawn.
  
  

Random Sample

• Representative group being surveyed. Every person in the population has an equal chance of being selected.
  
  

Correlation

• A statistical measure of the strength and duration of the relationship between two factors.
  
  

Correlation Coefficient

• The mathematical expression of that relationship ranges from -1 to +1. (Pearson product-moment correlation coefficient OR Pearson’s r).
  
  

Scatterplots

• A graph of plotted data points that show the relationship between two variables.
  
  

• The slope of the data suggests the direction of the relationship (positive or negative).
  
  

Positive Correlation

• The values of the variables tend to rise and fall together.
  
  

• Negative Correlation: As the value of one variable goes up, the other tends to go down.
  
  

• The amount of scatter suggests the strength of the relationship.
  
  

Illusory Correlations

• A perceived nonexistent relationship.
  
  

• When we believe there is a relationship between two variables, we notice and recall events that support our beliefs.
  
  

• Explains superstitious beliefs.
  
  

Experiment

• A research method in which the investigator manipulates one or more factors (independent variables) to observe their effects on some behavior or mental process (dependent variable) while controlling other relevant factors by random assignment of subjects.
  
  

Experimental Group

• Receives the treatment.
  
  

Control Group

• Does not receive the treatment but is the same in every other way.
  
  

Random Assignment

• Assigning participants randomly to the experimental and control groups to minimize differences between the groups.
  
  

Single-Blind Study

• Participants do not know which treatment group (experimental or control) they are in.
  
  

Double-Blind Study

• Both the participants and the experimenter do not know which treatment group the subjects are in.
  
  

Placebo Effect

• Experimental results caused by expectation alone.
  
  

Independent Variable (IV)

• The variable or factor that is manipulated by the experimenter. This is the cause in the cause/effect relationship.
  
  

Dependent Variable (DV)

• The variable being measured by the researcher. It is the effect that is dependent on the IV.
  
  

Confounding Variables

• Factors (other than the IV) that influence the DV. They are the result of poor planning, sloppy work, and bias.
  
  

Validity

• How well a test measures what it has been designed to measure.
  
  

Informed Consent

• The subject is given enough information on the study to make an informed decision on his/her participation.
  
  

Debriefing

• When an experimenter tells the subject more information about the study's purpose and procedures after the study is completed.