Shared Flashcard Set

Details

Stats- Chapter 14
Correlation coefficient.
16
Psychology
Undergraduate 1
04/17/2014

Additional Psychology Flashcards

 


 

Cards

Term
Predictor variable
Definition
independent variable.
Term
Outcome variable
Definition
dependent variable.
Term
Deterministic relationships
Definition
-every x has a y value
-linear and non-linear
Term
Linear relationships
Definition
y = a + b( x )
a = intercept
b = slope
Term
Probabilistic relationship
Definition
-when there are (possibly) many of y for each x
-linear or non-linear
ex. there are many weights for the height 5'7"
height = x
weight = y
Term
Conditional distributions
Definition
the distribution of y values
ex. weight for "height and weight" because weight is conditional to height
Term
Positive relationship
Definition
as x increases, y increases
Term
Negative relationship
Definition
as x increases, y decreases
Term
Correlation coefficient
Definition
a measure of the strength of linear association between two variables; strength is represented by how tightly clustered the points are to an imaginary like that runs through the scatterplot; represented by r
Term
Finding correlation coefficient
Definition
1. turn all data points into z-scores
2. multiply Zx by Zy for each pair
3. sum the products of all
4. divide by n - 1
Term
Homoscedasticity
Definition
all of the conditional distributions have the standard deviation as one another
Term
Bivariate normal distribution
Definition
-both x and y distribution are normal distributions (marginal distributions)
-for each value of x, there is a distribution of y values
-as x increases linearly, y values change linearly
-each conditional distribution is a normal distribution
-all conditional distributions have the standard deviation
Term
Marginal distributions
Definition
distribution of x and y variables in a bivariate normal distribution; x-scores and y-scores (according to mean and standard deviation) are normal distributions
Term
Sampling distribution
Definition
depends on p and sample size (n)
Term
lnr
Definition
natural logarithm for r
Term
Spurious correlation
Definition
meaning that the correlation between two variables is high because of a third-party variable.
Supporting users have an ad free experience!