Chapter 13 Iclicker Questions

Chapter 13 Iclicker Questions

Chapter 15 iClicker Questions

1. A correlation coefficient is a statistic that:

a) tells us how much variance there is in a distribution.

b) quantifies the relation between two variables.

c) tells us whether there is a significant difference between two factors.

d) quantifies the number of independent variables in an experiment.

2. Dr. Mc Mann conducts a research study and finds that on average, people with more education earn more money throughout their lifetimes than those with less education. What should Dr. Mc Mann conclude about the two variables, education-level and lifetime-income?

a) They are positively correlated.

b) They are negatively correlated.

c) There is no correlation between the two variables.

d) There is a significant difference between the two variables.

3.What type of correlation does the figure below best represent?

a) a positive correlation

b) a negative correlation

c) a curvilinear correlation

d) no correlation

4. Based on the figure below, how strong is the association between number of absences and mean exam grade?

a) small

b) medium

c) large

d) There is no association.

5. When a researcher obtains a significant correlation between two variables, in a study that she/he has completed, it is appropriate to draw all of the following types of conclusions EXCEPT:

a) that there is a relationship between the two variables.

b) the strength of the relationship between the two variables.

c) the direction of the relationship between two variables.

d) whether or not there is a cause/effect relationship between the two variables.

6. The Pearson r correlation coefficient is a statistic that:

a) quantifies a linear relation between two scale variables.

b) is used when a non-parametric test is needed.

c) allows us to determine if there is a significant difference between two variables.

d) is need to determine confidence intervals.

7. What type of graph is particularly useful for displaying a correlation?

a) histogram

b) bar graph

c) scatterplot

d) pie chart

8. When conducting hypothesis testing for the Pearson correlationcoefficient, r, we calculate degrees offreedom by subtracting 2 from thesample size. In Pearson correlation,the sample size is:

a) the number of participants.

b) the number of scores.

c) the number of variables.

d) All of the above could be correct.

9. Which of the following is the only value that can possibly be a Pearson r coefficient?

a) 2.83

b) -0.34

c)-4.9

d)-3.0

10. When a Pearson r correlation coefficient has a negative value (e.g., - 0.92) it means that:

a) there is no relationship between the two variables.

b) you have a confound in your research study.

c) you obtained negative results about your hypothesis.

d) as the value of one variable increases, the value of the other variable tends to decrease.

11. Psychometrics is the branch of statistics:

a) devoted to the study of individuals who suffer from psychological disorders.

b) that studies the history of the ANOVA and other such tests.

c) used in the development of tests and measurements.

d) that deals exclusively with qualitative analysis.

12. Each time Roberta takes a certain IQ test, she scores 100. It can be concluded that the IQ test is

a) valid

b) reliable

c) confounded

d) biased

13. When a test accurately measures what it is intended to measure, we say that the test is:

a) valid.

b) reliable.

c) confounded.

d) unique.

14. A technique that quantifies the degree of association between two variables after statistically removing the association of a third variable with both of those two variables is called a:

a) MANOVA.

b) mixed factorial ANOVA.

c) reliability test.

d) partial correlation.