Overconfidence Together with hindsight bias, can lead to overestimate our intuition “There is not reason for anyone to have a computer in their home.” Ken Olson, president of Digital Equipment Company, 1977

Three main components Curious eagerness Skeptically scrutinize competing ideas Open-minded humility before nature

“Smart thinking” Four elements Examines assumptions Discerns hidden values Evaluates evidence Assesses conclusions

Theory “mere hunch” Hypotheses Can be confirmed or refuted Operational Definition Replication (repeat)

an observation technique in which one person is studied in depth in the hope of revealing universal principles. Problem Study could be atypical

Looks at many cases at once  Word effects

 Population all the cases in a group being studied, from which samples may be drawn.  Note: Except for national studies, this does NOT refer to a country’s whole population.

 Random Sampling  a sample that fairly represents a population because each member has an equal chance of inclusion.

Describes behavior Does not explain behavior Stranger Paper

 Positive Correlations - is when 2 scores rise or fall together  Negative Correlations - Is when 2 sets of scores relate inversely – one set goes up and the other goes down

Comes from our need to make sense out of the world Coin flip Poker hand

 Randomly Assigning ◦ Control Group ◦ Experimental Group  Double-blind Procedure  Placebo Affect

 Independent The experimental factor that is manipulated; the variable whose effect is being studied.  Dependent The variable that may change in response to manipulations of the independent variable.

 Mode ◦ occurs the most  Mean ◦ arithmetic average  Median ◦ middle score

Normal Curve (bell shaped)

Statistical Significance The averages are reliable The differences between averages is relatively large Does imply the importance of the results