exam 4

Question 1

predictor

Answer 1

1st variable

Question 1

pearson’s r

Answer 1

correlation coefficient used for interval/ratio data in linear relationships

Question 2

criterion

Answer 2

2nd variable

Question 3

correlation coefficient range

Answer 3

-1 to +1 (0=none)

Question 4

correlation coefficient guidelines

Answer 4

-.20-+.20 = weak
.20-50 = moderate
.50+ = strong

Question 5

partial correlations

Answer 5

measure relationship between two variables while controlling a third variable by holding it constant

Question 6

coefficient of determination (R^2)

Answer 6

measure accuracy of correlational predictions (how much variability can be explained by predictor)

Question 7

R^2 guidelines

Answer 7

.01 = small effect
.09 = medium effect
.25 = large effect

Question 8

regression

Answer 8

allows us to make predictions using the line of best fit

Question 9

Y = bX + a

Answer 9

b = slope
a = y-intercept

Question 10

the error of prediction

Answer 10

Y - Ŷ

Question 11

total squared error

Answer 11

sum(Y − Ŷ)2

Question 12

best fitting line has the smallest…

Answer 12

total squared error (least squared error solution)

Question 13

regression test hypotheses are always

Answer 13

nondirectional

Question 14

regression test generic hypothesis

Answer 14

the equation using X does/does not account for a significant proportion of variance in the Y scores

Question 15

point always falling on regression line

Answer 15

(𝑋bar, Ybar)

Question 16

multiple regression

Answer 16

regression with 2 or more predictor variables for the single criterion variable

Question 17

beta/standardized b coefficients

Answer 17

can be compared, larger for one variable means it predicts more variance of criterion

Question 18

spearman rho coefficient used when

Answer 18

both variables measured on ordinal scale
or interval/ratio nonlinear

Question 19

point-biserial coefficient used when

Answer 19

one variable continuous (interval/ratio) and other two-level (nominal)

Question 20

phi coefficient Φ used when

Answer 20

association between 2 dichotomous variables (nominal)

Question 21

chi square x^2 used when

Answer 21

two nominal variables but with dichotomous or multiple group variables
can determine if one variable is independent of other categorical variable
determines if random or by chance

Question 22

contingency table

Answer 22

chi square table for frequency in each category

Question 23

NOIR

Answer 23

nominal - categories
ordinal - categorize + rank, distance between each is different
interval - rank + equal distances between scores
ratio - rank, equal distance, + true zero

Question 24

use mode when...

Answer 24

categorical data

Question 25

use mean when...

Answer 25

interval and ratio data, symmetrical distributions

Question 26

use median when...

Answer 26

ordinal data or skewed interval/ratio

Question 27

measures of variability

Answer 27

range, variance, standard deviation (most common)

Question 28

central limit theorem

Answer 28

reasonably large sample size (n=30) --> sampling distribution normally distributed

Question 29

type I error (α)

Answer 29

reject null when null is true

Question 30

type II error (β)

Answer 30

fail to reject null when H1 is true

Question 31

omnibus test

Answer 31

looks at effect overall (F), need to conduct post hoc test to look at which levels of IV are differing

Question 32

use z test....

Answer 32

sample of population, mean, and std dev

Question 33

use single sample t test....

Answer 33

sample mean and population mean, no std dev, <30

Question 34

independent 2 sample t test...

Answer 34

random assignment

Question 35

dependent 2 sample t test...

Answer 35

1 sample measured twice, or 2 related samples

Question 36

pearson's r APA results

Answer 36

pearson's r revealed significant relationship btwn .... r (n = #) = #, p = #, x-tailed, R^2 = #. Greater __ were associated with greater __.

Question 37

how to find b + a from spss

Answer 37

b = unstandardized for variable a = unstandardized for constant

Question 38

regression line APA results

Answer 38

the equation using X was/was not found to be a significant predictor of Y. F (df, df) = #, p = #, R^2 = #. More x predicted more y.