CHAPTER 5: ALTERNATIVES TO EXPERIMENTATION

• quasi-experiments - superficially resemble experiments, but lack their required manipulation
• pearson correlation coefficient - used to calculate simple correlations
• 4 properties of correlation coefficients

  1. linearity
  2. sign
  3. magnitude
  4. probability
• scatterplots - graphic display of pairs of data points on the x and y axes
• range truncation - artificial restriction of the range x and y
• outliers - extreme scores
• coefficient determination - estimates the amount variability that can be explained by a predictor variable
• correlational studies - do not create IV, randomly assign subjects to conditions, they cannot establish causal relationships
• multiple correlation - they want to know whether there is a relationship among three or more variables
• partial correlation - when we want to hold one variable constant to measure its influence on a correlation between two other variables
• multiple regression - predict behavior measured by one variable based on scores on two or more other variables
• causal modeling - creation and testing of models that suggest cause-and-effect relationships between behaviors
• 2 forms of causal modeling

  1. path analysis
  2. cross-lagged panel designs
• path analysis - researcher creates and tests models of possible causal sequences
• ex post facto - researcher examines the effects of already existing subject variables
• nonequivalent studies - compares the effects of treatments on pre existing groups of subjects
• longitudinal designs - same group of subjects is measured at different points in time
• cross-sectional designs - subjects at different developmental stages are compared at the same point in time