Question 9

Two schedules for giving rest were compared--the massed schedule and the spaced schedule. Twenty observations of the spaced schedule produced a mean of 26 errors. On the massed schedule 14 observations resulted in a mean of 36 errors. An a level of .05 was adopted and an F = 4.21 was obtained. What conclusion is appropriate?

Group of answer choices

Massed practice produces fewer errors than spaced practice.

The null hypothesis should be retained.

Spaced practice produces fewer errors than massed practice.

Question 10

Tukey Honestly Significant Difference test is a(n) ____ test.

Group of answer choices

neither of the descriptive alternatives is correct.

a priori;

post hoc;

both of the descriptive alternatives are correct;

Question 11

The value of K in an experiment depends on

Group of answer choices

the number of independent variable

the number in each sample.

the levels of the independent variable

the number of individuals in the entire study;

question 12

Statistical results that lead to the symbol: p > .05 means that the

Group of answer choices

null hypothesis should be rejected;

null hypothesis should be retained/failed to reject

There is not enough information for any conclusion

difference between the two means is statistically significant;

question 13

In an independent samples design the Hatfields had a mean score of 25 against a mean score of 26 for the McCoys. Low scores mean better performance. The researcher ran a two-tailed test with a at .05. A t value of 1.99 was found.

Group of answer choices

If df = 120, the McCoys are significantly better than the Hatfields.

If df = 120, the Hatfields are significantly better than the McCoys.

If df = 40, the Hatfields are significantly better than the McCoys.

If df = 120, the Hatfields and the McCoys are not significantly different.

If df = 40, the McCoys are significantly better than the Hatfields.

Question 14

A student conducted a before and after study on college statistics students to see if the course improved ability to reason. In a later study, she used a mother-daughter sample to assess generational differences in attitudes toward abortion. Her two designs are

Group of answer choices

independent, independent;

paired, paired;

independent, paired.

paired, independent;

Question 15

A test was conducted to see if energy drinks caused heart palpitation. Five groups were compared: each group drinking 1, 2, 3, 4, or 5 energy drinks per day. Anova was conducted, F value was significant. The null hypothesis was rejected: that there is a significant difference in heart palpitation speed among those who drank 1, 2, 3, 4 or 5 energy drinks per day. In any study that finds a significance, the researchers should always remain cognizant that:

Group of answer choices

They could have made a Type I error

No error can be made statistically

They could have made a Type II error

Type I or II error is possible.