Question 1 (Points: 1)

A study investigating the effects of nicotine on mental alertness, measures the test scores of participants on a cognitive task under one of three different randomly assigned conditions: (1) no nicotine, (2) moderate nicotine (whereby participants are given moderate amounts of nicotine), and (3) excessive nicotine (whereby participants are given high levels of nicotine). This research design could best be described as:

1. Between-subjects quasi-experimental

2. Between-subjects true experimental

3. Within-subjects quasi-experimental

4. Within-subjects true-experimental

5. Not enough information given regarding group assignment

Question 2 (Points: 1)

A sample of participants was selected from a normally-distributed population and achieved scores on a maths test of 59, 60, 60, 67, 65, 90, 89, 73, 74, 81, 71, 71, 83, 83, 88, 83, 84, 86, 78 and 79. It transpires that the population average for the test is 55, and the population standard deviation 12. The SEM is;

1. 2.18

2. 2.62

3. 2.68

4. 22.8

5. Not enough information provided

Question 3 (Points: 1)

From the data in Question 2, the estimated SEM is;

1. 2.18

2. 2.25

3. 2.68

4. 22.8

5. Not enough information provided

Question 4 (Points: 1)

Based on the data in Question 2, you decide to perform a hypothesis test with alpha of 0.01. You would conclude;

1. Z = 2.33, reject the null

2. Z = 6.33, accept the null

3. Z = 7.91, reject the null

4. Z = 8.25, reject the null

5. Z = 12.47, reject the null

Question 5 (Points: 1)

Your inferential test statistic (e.g., the t or the F) can be seen to be a ratio of ________ divided by ________.

1. Between-group variability; within-group (error) variability

2. Within-group (error) variability; between-group variability

3. The effect of the DV; the effect of the IV

4. Nuisance variables; confounders

Question 6 (Points: 1)

In a test of driving ability, the population mean is 3.87. For a sample of 25 adults who have taken advanced driving classes, the mean of driving ability is 4.39, with a standard deviation of 2.61. A researcher wants to determine whether the adults who have taken the class have improved their driving ability. The critical value for “t” at 0.05 is?

1. 1.69

2. 1.71

3. 2.06

4. 3.51

5. Not enough information provided

Question 7 (Points: 1)

From the information given in Question 6, the t value for this analysis is;

1. 0.52

2. 1.00

3. 1.69

4. 1.78

5. 2.03

Question 8 (Points: 1)

From the results of Question 6 and 7, would you reject or accept the null hypothesis (that the special driving class does not improve driving ability)?

1. Accept the null

2. Reject the null

3. Both 1 and 2

4. None of the above

Question 9 (Points: 1)

Hoping to see an improvement in students’ performance over the semester, the scores for mid-semester and final-semester exams (each out of 150) was collected from 17 students (ID number St1 to St17 below, each ID followed by mid-semester and final semester scores respectively); St1, 83.8, 95.2, St2, 83.3, 94.3, St3, 86.0, 99.5, St4, 82.5, 91.9 St5, 86.7, 100.3 St6, 79.6, 76.7, St7, 76.9, 76.8, St8, 94.2, 101.6, St9, 73.4, 94.9, St10, 80.5, 75.2, St11, 81.6, 77.8, St12, 82.1, 95.5, St13, 77.6, 90.7, St14, 83.5, 92.5, St15, 89.9, 93.8, St16, 86.0, 91.7, St17, 87.3, 98.0

You decide to do a one-tailed test. The alternative hypothesis you might want to examine is?

1. The final-semester mean score is less than the mid-semester mean score

2. The mid-semester mean score is the same as than the final-semester mean score

3. The final-semester mean score is greater than the mid-semester mean score

4. The score for any individual is greater for their final-semester exam compared to their mid-semester exam

5. The score for any individual is no different for their final-semester exam compared to their mid-semester exam

Question 10 (Points: 1)

The appropriate statistical test applied to the hypothesis in Question 9 is a;

1. One-way ANOVA

2. One-sample t-test

3. Repeated-measures t-test

4. Independent-samples t-test

5. One-sample Z-test

Question 11: (1 point)

Using the data in Question 9, the results are;

1. t(16) = 4.00

2. t(16 ) = 4.19

3. t(16) = 4.38

4. t(17) = 2.12

5. t(17) = 3.14

Question 12 (Points: 1)

From the hypothesis in Question 9 and using the statistical output from Question 11, the conclusion reached would be that;

1. The mean final-semester score is significantly different to the mean mid-semester score

2. The mean final-semester score is significantly less than the mean mid-semester score

3. The mean final-semester score not significantly different to the mean mid-semester score

4. The individual final-semester scores are not significantly different to the individual mid-semester scores

5. The mean final-semester score is significantly greater than the mean mid-semester score

Question 13 (Points: 1)

A group of “Experimental Design” students sit a “liking for statistics” questionnaire (out of 10, whereby the higher the score the more they like statistics) and score 8, 4, 6, 3, 1, 4, 4, 6, 4, 2, 2, 1, 7, 4, 3, 3, 2, 6, 3, 4. A group of psychology undergraduates who are yet to do “Experimental Design” also complete the questionnaire and score 2, 1, 1, 3, 2, 7, 2, 1, 3, 1, 0, 2, 4, 2, 3, 3, 0, 1, 2. The hypothesis is that, using an alpha of 0.05, attending Experimental Design lectures creates a different attitude to statistics than those who haven’t yet attended the unit.

The standard deviation for the “Experimental Design” students is?

1. 1.55

2. 2.10

3. 1.89

4. 1.93

5. 20

Question 14 (Points: 1)

From the data in Question 13, the degrees of freedom for the appropriate statistical test are?

1. 35

2. 37

3. 38

4. 39

5. 40

Question 15 (Points: 1)

The value of the appropriate statistic for the hypothesis test in Question 14 is?

1. 1.68

2. 1.89

3. 2.02

4. 2.66

5. 3.07

Question 16 (Points: 1)

For the hypothesis in Question 13, the critical value is;

1. 1.68

2. 1.89

3. 2.03

4. 2.65

5. 3.55

Question 17 (Points: 1)

A researcher wants to examine the cravings for cigarettes in smokers who have recently “kicked the habit”. Seventeen smokers are asked to give up smoking and record their cravings for cigarettes, on a scale between 1 and 50 (where 1 is “don’t crave at all” and 50 is “crave extremely”). After 5 days, six smokers record their craving scores as 15, 10, 25, 15, 20 and 15 respectively. After 20 days a different six smokers record their craving scores as 30, 15, 20, 25, 23 and 22 respectively. After 35 days, the final five smokers record their craving scores as 40, 35, 50, 43 and 45 respectively.

SStotal and SSwithin are?

1. 2 and 17

2. 722.4 and 2100

3. 27.06 and 271.7

4. 2355.9 and 384

5. 2792.5 and 392.5

Question 18 (Points: 1)

From the data in Question 17, you might determine that;

1. F(2, 16) = 5.12, p < 0.001

2. F(2, 14) = 26.17, p < 0.001

3. F(2, 14) = 35.94, p < 0.001

4. F(2, 16) = 392.5, p < 0.001

5. Not enough information provided

Question 19 (Points: 1)

From Question 18, you might conclude;

1. From this between-subjects design, cravings for cigarettes do not change significantly over time

2. From this between-subjects design, cravings for cigarettes increase significantly over time

3. From this within-subjects design, cravings for cigarettes increase significantly over time

4. From this between-subjects design, cravings for cigarettes decrease significantly over time

5. From this within-subjects design, cravings for cigarettes decrease significantly over time

Question 20 (Points: 1)

The researcher from Question 17 decides to run another study, this time examining anger levels in smokers who have recently given up smoking. The researcher recruits 8 recent “quitters” and measures their anger levels one week, two weeks and three weeks after their last cigarette. Anger levels are measured on a scale of 1 to 1-1000, where 1 is “no anger” and 1000 “extreme anger”.

The data is presented below. After each subject is three numbers, the anger levels after one, two and three weeks respectively;

Subject 1: 550, 570, 580

Subject 2: 440, 440, 470

Subject 3: 610, 630, 610

Subject 4: 650, 670, 670

Subject 5: 400, 460, 450

Subject 6: 700, 680, 710

Subject 7: 490, 510, 510

Subject 8: 580, 550, 590

The means for anger on each week are?

1. 535.75, 582.70 and 590.50

2. 551.50, 577.75 and 591.70

3. 552.50, 563.75 and 573.75

4. 557.75, 570.50 and 577.50

5. Not enough information provided

Question 21 (Points: 1)

The type of design of the study in Question 20 is?

1. Repeated-measures

2. Between-subjects

3. Within-subjects

4. Independent-samples

5. 1 and 3

6. 2 and 4

Question 22 (Points: 1)

The researcher is initially worried about the homogeneity of covariance (sphericity) in the data, and runs the appropriate test on PASW (SPSS). They find;

1. Homogeneity of covariance is satisfied, p > 0.05

2. Homogeneity of covariance is NOT satisfied, p > 0.05

3. Homogeneity of covariance is satisfied, p < 0.05

4. Homogeneity of covariance is NOT satisfied, p < 0.05

Question 23 (Points: 1)

The best way to represent the analysis in Question 20 is?

1. F(1.42, 9.94) = 3.66, p > 0.05

2. F(2, 14) = 3.66, p > 0.05

3. F(2, 14) = 3.66, p < 0.05

4. F(1, 7) = 14.96, p < 0.05

Question 24 (Points: 1)

From the analysis of the data from Question 20, you would conclude;

1. There is a statistical difference in anger across the three weeks, and this finding might be as a result of the low power in the study

2. There is a statistical difference in anger across the three weeks, and this finding might be as a result of the high power in the study

3. There is no statistical difference in anger across the three weeks, and this finding might be as a result of the low power in the study

4. There is no statistical difference in anger across the three weeks, and this finding might be as a result of the high power in the study

Question 25 (Points: 1)

A researcher compares three groups of participants to determine how temperature affects logical reasoning. Group 1 is in a room with a temperature of 15 degrees, Group 2 at 25 degrees, and Group 3 at 35 degrees. For this example, which group is the control group in the experiment?

1. Group 1

2. Group 2

3. Group 3

4. There is no control group