Correlations and Regressions 8.1 Flashcards
Habituation paradigm
Common method used to test the
mental categories of nonverbal
infants and nonhuman animals
Habituation paradigm method
• Habituate an organism to a
stimulus.
• Present a new stimulus.
(If they remain habituated, it means they treat it as the same category. If they don’t then they recognize it as categorically different)
• DV: difference score
• Can be used experimentally (with control)
or quasi-experimentally (shown here)
Correlation Research Types
- Causality
- Correlation (describe relationships) and Regression (predictions)
- Spurious correlations
- Regressions
Correlations
• tell you the relationship between two (bivariate) or more (multivariate) variables • Which variable is X, and which is Y does not matter • The correlation coefficient for linear relationships (r) ranges from -1 to +1 • Correlations can be positive or negative, and differ in strength
Correlation does not imply causation!
Spurious correlations – relationships that are correlated but not causally
related
Third variable
Third variable – a variable that causes changes in other variables and thus explains the
correlation
Regressions
Statistical models that allow you to predict the outcome of one variable based on
the values of another variable
• The regression line is the best-fit line (it minimizes error)
Simple linear regression
- 2 continuous variables
- y = a + bx
- y = response variable (DV)
- x = predictor variable (IV)
- b = regression coefficient (+/-)
Multiple linear regression
- y = a + b1x1 + b2x2 + … + bixi
- Complex relationships
- Controlling for other factors
Logistic regression
• Use a continuous variable to predict a binary categorical variable
• Reminder: causal relationships are warranted based on data collection methods, not models
or the names of the variables
Interpolation vs extrapolation
Extrapolation: prediction that go beyond the data