Deck 8: The T Test for Dependent Groups

Question 1

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-The derived t value from the formula is

A)0.938
B)4.500
C)4.417
D)0.200

Answer 1

0.938

Question 2

The __________________ effect is said to occur when extreme scores, which are measured again, tend to be closer to the mean.

A)correlation
B)regression
C)dependent
D)diminishing

Answer 2

regression

Question 3

The two-tailed test of significance protects against the Type ____ error better than the one-tailed test of significance.

A)I
B)II
C)III
D)IV

Answer 3

I

Question 4

The way in which the _________________ hypothesis is stated determines whether a test of significance is one-tailed or two-tailed.

A)null
B)alternative
C)neutral
D)pejorative

Question 5

Which of the following is not a way to increase the power of a t test?

A)increase the difference between two means
B)increase the number of participants
C)decrease within-subject variance
D)increase the number of independent variables

Question 6

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-The value of the numerator in the dependent t test formula for this problem is approximately

A)0.08
B)2.87
C)5.00
D)7.87

Question 7

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-The df for this problem are

A)24
B)12
C)11
D)10

Question 8

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-In nonstatistical language, what can be concluded?

A)the new drug works better
B)the new drug works no better than the old drug
C)because the mean number of seizures was lower for the new drug, this indicates that it works better than the old drug
D)because the mean number of seizures was higher for the old drug, this indicates that the old drug works better than the new drug

Question 9

Which of the following is not a name for the dependent t test?

A)repeated-measures t test
B)paired-samples t test
C)correlated t test
D)multiple t test

Question 10

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-The df for this problem are

A)0
B)8
C)5
D)14

Question 11

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-What statistical decision is appropriate?

A)retain the null hypothesis
B)reject the null hypothesis
C)reject the alternative hypothesis
D)the results are significant at p < .001

Question 12

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-The value of the numerator in the dependent t test formula for this problem is approximately

A)0.08
B)4.50
C)4.42
D).333

Question 13

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-Assume this t test had a nondirectional alternative hypothesis, and we will use the conventional level of statistical significance.The critical value (plus and minus) of the t test for this problem (obtained from Appendix B: t distribution) is

A)2.145
B)2.977
C)4.140
D)2.131

Question 14

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-In nonstatistical language, what can be concluded?

A)it appears that coffee drinking is associated with improved mood
B)coffee drinking does not cause mood improvement
C)coffee drinking is correlated with people's moods
D)the null hypothesis is retained

Question 15

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-What statistical decision is appropriate?

A)retain the null hypothesis
B)reject the null hypothesis
C)reject the alternative hypothesis
D)the results are significant at p < .05

Question 16

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-In statistical language, the results are significant at (and remember statisticians report the lowest p level possible)

A)p < .05
B)p < .01
C)p < .001

Question 17

One drawback of dependent t test designs versus independent t test designs is the degrees of freedom.Given the same number of participants in both designs, which has the greater degrees of freedom?

A)dependent
B)independent
C)they are equal

Question 18

A psychiatrist wishes to determine whether a new medication controls seizures better than the patients' previous medications. The number of seizures is recorded on previous and new medications for a period of 1 year for each patient. The research question is focused on determining whether there are differences between the two means of the numbers of seizures between the previous and new medications.

-Assume this t test had a nondirectional alternative hypothesis, and we will use the conventional level of statistical significance.The critical value (plus and minus) of the t test for this problem (obtained from Appendix B: t distribution) is

A)2.179
B)2.201
C)3.106
D)4.437

Question 19

A psychologist wishes to determine whether drinking coffee improves one's mood. The psychologist hangs out at the Café Coffay and asks customers to fill out a 10-point good-mood, bad-mood questionnaire (where 10 = great mood and 1 = bad mood) before and after their first cup of coffee that day. The research question is whether there is any evidence that drinking coffee improves mood.

-The derived t value (either + or -) from the formula is

A)5.00
B)7.87
C)3.44
D).05

Question 20

Design 3 of the dependent t test controls for the

A)order of presentation
B)regression effect
C)diminishing effect
D)abuse of power