PSYC232 Test 3, Week 8 Flashcards
(31 cards)
Who is considered the father of behavioral and educational statistics?
Sir Francis Galton.
What was Galton’s goal in studying mental processes?
To measure psychological phenomena like boredom using observable behaviors (e.g., fidgets per breath).
Why might Galton’s boredom measurement not apply to kids or older adults?
Due to issues with reliability and validity.
What is linear regression?
Predicting a score on one variable using another variable.
What is multiple regression?
Predicting a score on one variable using more than one predictor variable.
What does the regression equation look like?
Y′ = intercept + (predictors) + error
What does “predict” in a test question usually indicate?
That regression is being used.
What are the key assumptions of regression?
Independence of observations
Normal distribution of variables
Linearity between predictors and outcome
Homoscedasticity of residuals
What is homoscedasticity?
Equal variance of residuals across all levels of the predictor(s).
What does R represent in regression output?
The correlation between the predicted and actual outcome values.
What does R² represent?
The proportion of variance in the outcome explained by the model.
What is Adjusted R²?
A corrected R² that accounts for the number of predictors in the model.
How is model error calculated?
Error = 1 − R2
What does Box 1 in Jamovi show?
Overall model fit and significance (e.g., F-test, R²).
What does Box 2 in Jamovi show?
The contribution of each predictor (e.g., B, β, t, p-values).
What does the unstandardized coefficient (B) represent?
The change in the outcome for a one-unit change in the predictor.
What does the standardized coefficient (β) represent?
The change in standard deviation units of the outcome per SD unit change in the predictor.
What is the main goal of multiple regression?
To determine the unique contribution of each predictor to the outcome variable, controlling for other predictors.
When is a predictor considered significant in multiple regression?
When it explains variance in the outcome that is not explained by other predictors.
How is interpretation in multiple regression similar to linear regression?
The interpretation is the same, but in multiple regression, each predictor’s effect is assessed while controlling for all other predictors.
How do you interpret a predictor in multiple regression?
As the amount of change in the outcome associated with a one-unit change in the predictor, controlling for other variables.
Example interpretation: “A one-unit increase in attractiveness was associated with a .809 increase in romantic interest, controlling for gender.” What does this mean?
Attractiveness has a positive effect on romantic interest, independent of gender.
Can categorical variables be used in regression?
Yes, especially if they have only two groups.
How are categorical variables interpreted in regression?
As the difference in the outcome between the two groups, based on the numeric coding (e.g., 1 = men, 2 = women).
