Question 1 1 pts
A researcher was interested in stress levels of lecturers during lecturers. She took the same group of 8 lecturers and measured their anxiety (out of 15) during a normal lecture and again in a lecture in which she had paid students to be disruptive and misbehave. Based on the SPSS output, how would you interpret these results?
Group of answer choices
- There were no significant differences between anxiety levels in normal lectures and in those in which students misbehaved.
- We can’t tell any of the above from the output given.
- Anxiety levels were significantly higher in lectures in which students misbehaved.
- Anxiety levels were significantly lower in lectures in which students misbehaved.
Question 2 1 pts
A psychologist was interested in whether there was a gender difference in the use of email. She hypothesized that because women are generally better communicators than men, they would spend longer using email than their male counterparts. To test this hypothesis, the researcher sat by the email computers in her research methods laboratory and when someone started using email, she noted whether they were male or female and then timed how long they spent using email (in minutes). What should she report?
Group of answer choices
- Females and males did not significantly differ in the time spent using email, t(14) = –1.90, p = .10.
- Females and males did not significantly differ in the time spent using email, t(7.18) = –1.90, p = .10.
- Females spent significantly longer using email than males, t(14) = –1.90, p < .05.
- Females and males did not significantly differ in the time spent using email, t(7.18) = –1.90, p < .05, one-tailed.
Question 3 1 pts
A researcher was interested in the effects of emotion-evoking music on exam performance. Before their SPSS exam, a lecturer took one group of students to a room in which calming music was being played. A different group of students were taken to another room in which the ‘death march’ was being played. The students then did the exam and their marks were noted. The SPSS output is below. The experimenter made no predictions about which form of support would produce the best exam performance. What should he report?
Group of answer choices
- Marks for students receiving positive music before the exam did not significantly differ from students receiving negative music, t(23.12) = 2.05, p = .052.
- Students receiving positive music before the exam did significantly better than those receiving negative music, t(38) = 2.05, p = .047.
- Marks for students receiving positive music before the exam did not significantly differ from students receiving negative music, t(38) = 2.05, p = .047.
- Students receiving positive music before the exam did significantly better than those receiving negative music, t(23.12) = 2.05, p < .05, one-tailed.
Question 4 1 pts
An independent t-test is used to test for:
Group of answer choices
- Differences between means of groups containing different entities when the data are not normally distributed or have unequal variances.
- Differences between means of groups containing different entities when the sampling distribution is normal, the groups have equal variances and data are at least interval.
- Differences between means of groups containing the same entities when the data are normally distributed, have equal variances and data are at least interval.
- Differences between means of groups containing the same entities when the sampling distribution is not normally distributed and the data do not have unequal variances.
Question 5 1 pts
An paired-samples t-test is used to test for:
Group of answer choices
- Differences between means of groups containing different entities when the sampling distribution is normally distributed, and the data have equal variances and are at least interval.
- Differences between means of groups containing the same entities when the sampling distribution is normally distributed, and the data have equal variances and are at least interval.
- Differences between means of groups containing different entities when the sampling distribution is not normally distributed.
- Differences between means of groups containing the same entities when the sampling distribution is not normally distributed and the data do not have unequal variances.
Question 6 1 pts
A researcher measured a group of people’s physiological reactions while watching horror films and compared them to when watching comedy films. The resulting data were normally distributed. What test should be used to analyse the data?
Group of answer choices
- Independent t-test.
- Mann–Whitney test.
- Wilcoxon signed-rank test.
- Paired-samples (dependent or related) t-test.
Question 7 1 pts
- Which of the following sentences is an accurate description of the standard error?
Group of answer choices
- It is the standard deviation of the sampling distribution of a statistic.
- It is the same as the standard deviation.
- It is the observed difference between sample means minus the expected difference between population means (if the null hypothesis is true).
- The standard deviation squared.
Question 8 1 pts
If you use a paired samples t-test:
Group of answer choices
- The same participants take part in both experimental conditions.
- Other things being equal, you do not need as many participants as you would for an independent samples design.
- All of these are correct.
- There ought to be less unsystematic variance compared to the independent t-test.
Question 9 1 pts
Participants rated their mood score out of 20 before and after listening to Reign in Blood by the thrash metal band Slayer.
Before Listening to Slayer | After Listening to Slayer |
5 | 14 |
8 | 5 |
9 | 17 |
4 | 18 |
3 | 8 |
15 | 19 |
12 | 14 |
6 | 16 |
What is the null hypothesis of this study?
Group of answer choices
- Listening to Slayer is no better than listening to no music at improving mood score.
- Listening to Slayer does not affect mood.
- Listening to Slayer increases mood score.
- Listening to Slayer decreases mood score.
Question 10 1 pts
The t-statistic:
Group of answer choices
- When significant, indicates an important finding.
- Is accurate only when using large samples.
- Is the standard deviation of the sampling distribution of a statistic.
- Is the ratio of the systematic variation to the unsystematic variation.