Stats (Correlation/prediction)

Question 1

correlation techniques are used to determine the degree of ______ between two or more variables and to make predictions about status or scores on one or more criteria based on status or scores on one or more ______

Answer 1

association; predictors

Question 2

A scattergram illustrates the relationship between two variables. The wider the scatter of data points in the scattergram, the ______ the correlation between the variables

Answer 2

lower

Question 3

a correlation is a number that indicates the average degree of association between variables. The choice of a coefficient is based primarily on the scale of measurement of the variables being correlated. For example, the Pearson r is used when both variables are measured on a(n) ______ scale, while _______ is used when both variables are ranks

Answer 3

interval or ratio; Spearman rho

Question 4

the _____ correlation coefficient is appropriate when one variable is a true dichotomy and the other is measured on an interval or ratio scale, and the ______ correlation coefficient is appropriate when one variable is an artificial dichotomy and the other is measured on an interval or ratio scale

Answer 4

point biserial; biserial

Question 5

The Pearson r and coefficients derived from it range in value from _______

Answer 5

-1.0 to +1.0

Question 6

The magnitude of the coefficient indicates the _____ of the relationship, while the sign indicates its ______

Answer 6

strength; direction

Question 7

Use of the Pearson r is based on three assumptions:

1. there must be a _______ relationship between variables
2. there must be and ________ range os scores on both variables
3. there must be ________, or the same range of Y scores at every X value

Answer 7

linear; unrestricted; homoscedasticity

Question 8

a large correlation coefficient for two variables alone cannot be interpreted as evidence of a(n)______ relationship between X and Y but can be interpreted in terms of shared variability. This is done by the _____ coefficient

Answer 8

causal; squaring

Question 9

if the correlation coefficient for X and Y is .30, this means that ____% of variability in Y is explained by variability in X

Answer 9

9

Question 10

regression analysis is the technique that makes it possible to use predictor (X) score to predict or estimate a ______ (Y) score

Answer 10

criterion

Question 11

an assumption underlying the use of regression analysis is that the relationship between X and Y can be described by a ______

Answer 11

straight line

Question 12

the position of the regression line in a scattergram is identified using the _______ criterion, which locates the regression line so that error in prediction is minimized

Answer 12

least squares

Question 13

A high school counselor uses a battery of tests to help high school juniors and seniors choose a college major. Which of the following multivariate techniques would be most helpful in this situation?

Answer 13

discriminant function analysis
(Discriminant function analysis is used to predict or estimate a person’s status on a single nominal criterion from two or more predictors.)

Question 14

Multiple regression

Answer 14

used to predict status on a single continuous criterion from scores on two or more predictors.

Question 15

Path analysis

Answer 15

a causal modeling technique that is an extension of multiple regression and is used to test a theory about the causal relationships among a set of variables.

Question 16

Canonical correlation

Answer 16

the appropriate technique when two or more predictors will be used to predict status on two or more continuous criteria.

Question 17

Eta is used to:

Answer 17

determine the correlation for two variables that have a nonlinear relationship.

Question 18

The correlation coefficient for Test A and Test B is -.40. This means that ___% of variability in Test A scores is shared in common with Test B scores.

Answer 18

16
(A measure of shared variability is obtained by squaring the correlation coefficient: -.40 squared is .16. Therefore, 16% of variability in Test A scores is shared with (or accounted for by) variability in Test B scores.)

Question 19

To determine the degree of association between gender and attitude toward abortion when the attitude measure represents an interval scale, you would use which of the following correlation coefficients?

Answer 19

point biserial
(The point biserial coefficient is the appropriate coefficient when one variable represents a true dichotomy and the other is measured on an interval or ratio (continuous) scale.)

Question 20

The Pearson r

Answer 20

the appropriate correlation coefficient when both variables are measured on an interval or ratio scale.

Question 21

The phi coefficient

Answer 21

used when both variables are true dichotomies.

Question 22

The contingency coefficient

Answer 22

used to determine the degree of association between two nominal variables.

Question 23

When using path analysis, you are:

Answer 23

confirming a model involving one-way causal flow between a set of observed variables.

Question 24

LISREL

Answer 24

more complex than path analysis and not only includes two-way paths but also takes into account both observed variables and the latent traits those variables are believed to measure.