Research Methods & Statistics Exam 2

The value of Pearson's r ranges between ______.

-1.0 and +1.0

If N = 15 for a one-sample t test, then df = ______.

14

Joyce asks individuals leaving a gym how many times a week they tend to exercise at the gym. She finds that on average, her participants exercise 3.67 times a week (SD = 2.00), 95% CI [1.44, 5.90]. This suggests that her mean of ______ likely represents a population mean between ______ and ______.

3.67; 1.44; 5.90

Shawn examines the relationship between creativity and academic honesty and finds the coefficient of determination equals .33 or r2 = -.33. This means that ______.

33% of the variability in academic honesty is accounted for by knowing its relationship with creativity

The statistic used to determine whether a linear relationship exists between two interval/ratio variables is the ______.

Pearson's r

You believe that students' anxiety is related to test scores in Research Methods. Which of the following represents a directional alternative hypothesis for your study?

Students' anxiety will be negatively related to their test scores in Research Methods.

Suppose the type of computer game (violent vs. scavenger hunt) really has an impact on players' aggression but you do not reject the null hypothesis. You have made ______.

Type II error

If we want to find whether the first year class at our college has higher scores on the SAT writing test than the national average for the test, we would compute ______.

a one-sample t test

In an experiment examining the effect of type of cell phone ring (popular song vs. piano playing) on distraction, the null hypothesis would predict ______.

distraction levels will not differ for the two types of cell phone rings

The region of rejection is generally the ______ of the sampling distribution.

extreme 5%

Type 2 error

falsely ACCEPTING the null hypothesis (the null hypothesis was not correct)

Type 1 error

falsely REJECTING the null hypothesis (the null hypothesis is correct)

In order for the results of a one-sample t test to be significant, the computed t value must be ______.

greater than the critical t value listed in the t table for our degrees of freedom (df) and p value

The strength of the relationship is evident from ______ and the direction of the relationship is evident from ______ in a correlation coefficient.

how close the correlation coefficient is to the absolute value of 1.0; the sign of the coefficient

Anne and Jack are examining variables related to self-control. Anne finds r = +.40 between percentage of salary saved and self-control while Jack finds r = -.60 between impulsivity and self-control. Which variable is more strongly related to self-control?

impulsivity

A correlational design ______.

is a type of study that tests the hypothesis that variables are related

The 99% confidence interval will be ______ the 95% confidence interval.

larger than

In order to compute a one-sample t test, we must ______.

measure our variable on an interval or ratio scale

A null hypothesis is always stated in terms of ______.

no difference between groups or no relationships

When we find statistical significance, it suggests that our results were ______.

not due to chance alone and do not belong to the sampling distribution defined by the null hypothesis

A researcher finds a p value of .17. Using the standard criterion for statistical significance, are the results statistically significant? And as such, should the researcher reject or retain the null hypothesis?

not statistically significant, retain the null

If we want to find whether the first year class at our college has higher scores on the SAT writing test than the national average for the test, our directional alternative hypothesis (Ha) might state ______.

our first year class will score higher than the national average for the SAT writing test

The relationship between two variables is such that both variables are decreasing. This relationship shows a ______.

positive correlation

The order of the hypothesis testing process is described by which of the following?

state hypotheses, define the sampling distribution, collect data, compare results to sampling distribution, decide whether to reject or retain the null hypothesis (SDCCD - State, Define, Collect, Compare, Decide)

The purpose of inferential statistics is to allow researchers to determine whether

the outcome of a study is typical or unusual for a particular sampling distribution

Practical significance refers to ______.

the usefulness of our results in everyday life

Correlation is the statistic used to assess ______.

the validity and reliability of measures