 Aim: purpose  Independent Variable (IV): manipulated variable  Dependent Variable: (DV) measured variable  Operationalized Variable: Written so what is being measured is clear.

 Experimental Hypothesis: predicts the relationship between the IV and DV. What will be the outcome?  Control condition: comparison of two conditions related to IV.  Null Hypothesis: predicts no result or will be due to chance.

 Laboratory Experiments  Pro: Strict control of variables  Cons: Artificial, not real world  Field Experiment: Natural Environment, but variables are manipulated.  Has Ecological Validity  Natural Experiment: no control over variables

 Confounding variables: undesirable variables that influence the relationship between IV and DV.  Demand Characteristics ▪ Hawthorne Effect ▪ Solution: Single Blind Control  Researcher Bias ▪ Solution: Double Blind Control  Participant Variability ▪ Sample Problems affect DV. ▪ Solution: Random sampling  Artificiality ▪ Lack of Ecological Validity

 Positive Correlation: Both variables affected in same way.  Negative Correlation: X increases, Y decreases  Ex. TV watching, Exam scores  Bidirectional ambiguity: Which one caused which?

 People who often ate Frosted Flakes as children had half the cancer rate of those who never at the cereal.  Conversely, Those who often ate oatmeal as children were four times more likely to develop cancer than those who did not.  Are these good correlations?

 Increased ice cream consumption = higher crime rates.  High TV watching = High obesity  What are some possible third factor explanations?  Bidirectional Ambiguity?