Deck 15: Correlation and Regression

Question 1

Which term or phrase below best describes correlation research?

A) cause and effect
B) experimentation
C) relationship
D) Both "a" and "c" are correct.

Answer 1

C

Question 2

A positive correlation coefficient indicates

A) a favorable outcome.
B) scores from two variables that move in opposite directions.
C) scores from two variables that move in the same direction.
D) when to reject the null hypothesis.

Answer 2

C

Question 3

A negative correlation coefficient indicates

A) a favorable outcome.
B) scores from two variables that move in opposite directions.
C) scores from two variables that move in the same direction.
D) when to reject the null hypothesis.

Answer 3

B

Question 4

A positive correlation coefficient suggests that

A) high scores on Y are associated with low scores on X.
B) high scores on Y are associated with high scores on X.
C) low scores on Y are associated with low scores on X.
D) Both "b" and "c" are correct.

Question 5

A negative correlation coefficient suggests that

A) high scores on Y are associated with low scores on X.
B) high scores on Y are associated with high scores on X.
C) low scores on Y are associated with low scores on X.
D) Both "b" and "c" are correct.

Question 6

______________________ is suggested if the data points of a scatterplot are widely dispersed.

A) A positive correlation
B) A negative correlation
C) A weak correlation
D) A strong correlation

Question 7

Which of the following statements reflects a positive correlation?

A) As the temperature increases, the cost of heating decreases.
B) As class attendance drops, performance on exams decreases.
C) As television viewing decreases, time spent outdoors increases.
D) Increased exercise is associated with less body fat.

Question 8

Which of the following statements reflects a negative correlation?

A) The less time a company spends on marketing, the fewer customers they tend to have.
B) The longer you go without food, the hungrier you will be.
C) As running pace increases, the amount of time it takes to get to the finish line decreases.
D) As temperature decreases, the cost spent on air conditioning goes down.

Question 9

The null hypothesis for the Pearson correlation

A) is that there is no relationship between the two variables.
B) asserts a non-zero correlation in the population.
C) assumes a correlation equal to 1 in the population.
D) asserts a non-zero correlation in the sample.

Question 10

The correct notation for a non-directional alternative hypothesis for a Pearson correlation is

A) H₁: p ≥ 0
B) H₁: p = 0
C) H₁: p ≠ 0
D) H₁: p < 0

Question 11

Which of the following is the correct notation for a directional alternative hypothesis for a Pearson correlation?

A) H₁: p ≥ 0
B) H₁: p ≠ 0
C) H₁: p = 0
D) H₁: p < 0

Question 12

If you were conducting a hypothesis test for a Pearson correlation for a sample size of 18, df would be ______.

A) 20
B) 16
C) 17
D) 19

Question 13

If a Pearson correlation is close to 0, the data points on the scatterplot

A) will be scattered randomly throughout the graph.
B) will be close to the regression line from the lower left corner to the upper right corner.
C) will be close to the regression line from the lower right corner to the upper left corner.
D) will be close to the regression line which runs straight across the middle of the graph.

Question 14

A negative correlation is also called a(n) ________________ relationship.

A) internal
B) inverse
C) convex
D) converse

Question 15

If the result of your calculation of the Pearson correlation coefficient is ________, you have made a mistake.

A) −.00
B) −.99
C) +1.21
D) +.76

Question 16

Which of the following represents the coefficient of determination?

A) r²
B) 1 - r²
C) 1
D) r² - 1

Question 17

Which of the following represents the coefficient of nondetermination?

A) r²
B) 1 - r²
C) 1
D) r² - 1

Question 18

If r = .82, what is the coefficient of determination?

A) .18
B) .2417
C) .3276
D) .6724

Question 19

If r = .64, what is the coefficient of nondetermination?

A) .4096
B) .5904
C) .36
D) .7321

Question 20

If overlapping circles are used to illustrate the relationship between the coefficients of determination and nondetermination, each circle represents

A) the coefficient of determination.
B) the coefficient of nondetermination.
C) the total variability for one of the variables.
D) the amount of shared variability.

Question 21

If overlapping circles are used to illustrate the relationship between the coefficients of determination and nondetermination, the area of overlap represents

A) the coefficient of determination.
B) the coefficient of nondetermination.
C) the total variability for one of the variables.
D) the amount of non-shared variability.

Question 22

If overlapping circles are used to illustrate the relationship between the coefficients of determination and nondetermination, the area of non-overlap represents

A) the coefficient of determination.
B) the coefficient of nondetermination.
C) the total variability for one of the variables.
D) the amount of shared variability.

Question 23

A correlation of r = .69 is found between scores on a biology test and scores on a chemistry test. What is the coefficient of determination?

A) .48
B) .31
C) 1.38
D) .52

Question 24

If a strong positive correlation between two variables is found, which of the following statements is legitimate?

A) A cause and effect relationship may be indicated.
B) X causes changes in Y.
C) Y causes changes in X.
D) All of the above are true.

Question 25

It is called __________________ when a sample is used that limits the scores on one or more variables more so than would be found in the population.

A) regression of the variables
B) understating the value
C) limiting the potential
D) restricting the range

Question 26

Uses of the Pearson correlation include measuring the reliability and validity of assessment instruments and _________________.

A) identifying outliers
B) prediction
C) establishing cause and effect
D) determining the strength of curvilinear relationships.

Question 27

If an assessment designed to measure introversion is given to the same people two weeks apart and their scores are similar on both occasions, ______________ has been demonstrated.

A) reliability
B) validity
C) confidence
D) coincidence

Question 28

If there are ten questions about analytical geometry on your biology test, the test shows a lack of _____________.

A) determination
B) variance
C) reliability
D) validity

Question 29

_______________ is used to predict the value of a score on one variable by knowing the score on the other.

A) Restricting the range
B) Sampling
C) Regression analysis
D) Repeated measures

Question 30

______________ variables are used to estimate values on another variable in regression analysis.

A) Criterion
B) Predictor
C) Probability
D) Theoretical

Question 31

The variable that is estimated from predictor variables in regression analysis is called the ______________ variable.

A) criterion
B) predictor
C) probability
D) theoretical

Question 32

If a college admissions officer uses high school GPA to predict college GPA, high school GPA is the ___________ variable.

A) criterion
B) predictor
C) probability
D) theoretical

Question 33

If a college admissions officer uses SAT scores to predict college GPA, college GPA is the ___________ variable.

A) criterion
B) predictor
C) probability
D) theoretical

Question 34

Using more than one predictor variable is referred to as _____________ regression analysis.

A) cumulative
B) complex
C) simple
D) multiple

Question 35

The straight line that runs through a scatterplot used for predicting Y-scores from given X-scores is called the

A) line of expectancy.
B) regression line.
C) line of best fit.
D) Both "b" and "c" are correct.

Question 36

The ____________ is the component of the regression equation that tells how much and in what direction the regression line slants.

A) descent
B) angle
C) slope
D) Y-intercept

Question 37

The _____________ is the point where the regression line cuts across the Y-axis.

A) descent
B) angle
C) slope
D) Y-intercept

Question 38

In the regression equation, "b" symbolizes the ____________.

A) coefficient of determination
B) coefficient of nondetermination
C) slope
D) Y-intercept

Question 39

Indicate whether the correlations below would most likely be positive or negative.
a. Ice cream sales and outside temperature.
b. Number of days without rain and length of grass.
c. Age and agility.
d. Amount of coffee consumed and level of alertness.

Question 40

Write the null and alternative hypotheses in symbolic form for a nondirectional Pearson correlation test.

Question 41

Write the null and alternative hypotheses in symbolic form for a negative Pearson correlation.

Question 42

What is meant by a negative correlation between two variables?

Question 43

How would you describe the strength of a correlation of r = .04?

Question 44

Explain what is meant by the coefficients of determination and nondetermination.

Question 45

Given a correlation coefficient of r = .85, what is the coefficient of determination?

Question 46

Given a correlation of r = .89, what is the coefficient of nondetermination?

Question 47

Summarize why caution should be exercised when interpreting correlations as pertaining to the following:
a. cause and effect
b. restricted range
c. outliers

Question 48

Describe the three main uses of the Pearson correlation that are discussed in your text.

Question 49

A regression equation is Y' = .72X + 4.98 with X being sores on messiness and Y being scores on creativity. What creativity score would be predicted for a person who scored 11 on messiness?

Question 50

Based on the summary data below, predict the Extroversion (Y) scores for people who scored 10, 15, and 20 on Happiness (X). (Hint: you will need to calculate the slope and Y-intercept to use in the regression equation.
r = .77
M_x = 18.87
s_x = 2.75
M_y = 7.25
s_y = 2.12

Question 51

Calculate r for the following set of scores:

Question 52

Calculate a Pearson correlation for the following scores:

Question 53

A sleep researcher is interested in the relationship sleep and memory. A random sample of 7 participants is selected for the study. Scores on the number of hours slept (X) and the number of memory errors (Y) are shown below. Conduct a nondirectional Pearson correlation test with α = .01.

Question 54

Below are data for the number of hours that a random sample of students spent studying (X) and their score on a 25-point quiz (Y). Are longer study sessions related to higher scores? Conduct a Pearson correlation test, one-tailed at α = .01.