Unit II

Tendency to believe, after learning an outcome, that one would have foreseen it

The “I knew it all along” phenomenon

Tendency to think we know more than we do

Answer the following questions in complete sentences. You will be adding more to this later.1. Give an example of hindsight bias from your

own life.2. Give an example of overconfidence from your

own life.

E = AriesB = TaurusC = GeminiA = CancerF = LeoD = Virgo

K = LibraH = Scorpio I = SagittariusL = Capricorn J = AquariusG = Pisces

Case study - studies one person in depth in hopes of revealing universal principles

Survey - uses a representative sample of people to estimate attitudes or reported behaviors of a whole population ◦ Population - all the cases in a group being

studied from which samples may be drawn◦ Random sample - every member of a population

has an equal chance of inclusion

Naturalistic observation - observing and recording behavior in a natural environment

3. Give an example of a study when researchers might use a case study.

4. Give an example of an experiment when researchers might use a survey. How could they ensure a random sampling of the population?

Measures how closely two things vary together and thus how well either one predicts the other

Graphed on a scatterplot and measured with a correlation coefficient◦ Positive = two sets of scores rise or fall together◦ Negative = two sets of scores relate inversely◦ zero = weak correlation

CORRELATION DOES NOT PROVE CAUSATION

The perception of a relationship where none exists

5. Give an example from your life of an illusory correlation.

6. What can you conclude from this statement: Eating saturated fat and the likelihood of contracting cancer are positively correlated.

Random assignment - assigning participants to experimental and control groups by chance

Double blind procedure - neither the research participants nor the research staff know whether participants have received the treatment or a placebo

Placebo effect - experimental results caused by expectations alone

Experimental group - group exposed to treatment

Control group - group not exposed to treatment

Independent variable (IV) - experimental factor that is manipulated

Confounding variable - factor other than the IV that might produce an effect in an experiment

Dependent variable - outcome factor; variable that may change in response to manipulations of the IV

Statistical significance - observed difference is likely not due to chance variation between the samples

7. Develop a hypothesis and an experiment to test the hypothesis. Indicate the experimental and control groups, and independent, dependent and confounding variables.

8. Someone participating in a study on the effects of alcohol on perception is told by the experimenter that he has been assigned to the high dose group. What is the problem with this?

Nature vs. nurture Hindsight bias Overconfidence Hypothesis Research methods –

What is it? When is it used? Benefits and limitations?◦ Case study◦ Survey◦ Natural observation

Ethics in research

Correlational studies◦ Positive correlation◦ Negative correlation◦ Correlation coefficient◦ Relationship between

correlation and causation Experiments

◦ Independent variable◦ Dependent variable◦ Control group◦ Experimental group◦ Random sample◦ Population◦ Placebos