
Four Basic Canons of Science
 Determinism: Events have meaningful, systematic causes.
 Empiricism: The method of making observations. (Making observations is the best method.)
 Parsimony: If we have two competing theories, we should choose the simpler or more frugal of the two.
 Testability: You must be able to realistically test the theory (involves Validation, Falsification & Qualification).

QuasiExperiment
Naturally occurring grouping variable, but analyzed like an experiment.

Independent variables vs. grouping variables
 Variable that is manipulated by experimenter
 In a Quasiexperiment, called the grouping variable (GV)

Scales of Measurement: NOIR
 Nominal: – Numbers are names only, no real order.
 – Use Frequencies and ChiSquare
 Ordinal:– rank ordered, but don’t know how far apart scores are.
 Sprite is favorite, coke is 2nd
 Interval:– Tells how far apart values are, but no true 0 point. Equal interval between units.
 Sprite>Coke>>>>Pepsi>>>>>>>Tea
 Ratio: – like interval but with a true 0 point
 Temperature

Descriptive Statistics
 Measures of Central tendency: Mean, median, mode
 Measures of Variability: Range, variance, standard deviation
 Range is the difference between the largest and smallest value
 Variance is the average squared deviation of each score from the mean
 Standard deviation is the square root of the variance.


Type I and Type II errors
Type I error: a true null hypothesis is rejected (false positive)
Type II error: Failing to regect a false null (false negative)

Factors, levels, and between/within subjects
designs
 Factors: # of IVs
 Levels: Treatment conditions PER IV
 Between/Within Group: Between People are in different groups. Within People test out all groups and compare to self.

Generalizability
 Statistical generalizability: Allows you to generalize to the population from which you randomly selected.
 Practical generalizability: You can generalize to similar individuals (i.e., college students)
 Situational Generalizability: Can findings from the lab be applied to real life? How is the research setting different from other settings? How were the variables (IV’s & DV’s) operationalized?

Grouping variable
 Typically categorical
 Male, female
 1, 2, 3, 4
 etc

The Values
 T= Grand Total
 t= # of grand totals (always 1)
 A= Total for each condition
 a= # of levels for the IV
 AS= Individual scores
 s= # of participants per condition
 as= Total # of participants
 [T]=T^{2}/as
 [A]=A_{1}^{2}+A_{2}^{2}/s
 [AS]=AS^{2}

