Deck 7: How Can I Tell If Scores Differ Between Two Groups Independent T Test

Question 1

Which of the following datasets is likely to be significant?

A) A dataset with more between groups variance than within groups variance
B) A dataset with less between groups variance than within groups variance
C) A dataset with the same amount of between groups variance and within groups variance
D) A dataset with half the amount of between groups variance than within groups variance

Answer 1

A
Explanation: There should be more between groups variance than within groups variance for your dataset to be significant.

Question 2

You have calculated that a dataset has between groups variance with a value of 15 and a within groups variance of 3. What would the calculated t statistic be, and do you think the analysis would be significant or not significant?

A) 3, not significant
B) 3, significant
C) 0.2, not significant
D) 0.2, significant

Answer 2

D
Explanation: t = Between group variance/within group variance, therefore 15/3 = 5

Question 3

You have calculated that a dataset has between groups variance with a value of 4 and a within groups variance of 8. What would the calculated t statistic be, and do you think the analysis would be significant or not significant?

A) 2, not significant
B) 2, significant
C) 0.5, not significant
D) 0.5, significant

Answer 3

C
Explanation: t = Between group variance/within group variance, therefore 4/8 = 0.5

Question 4

You have calculated a t statistic of 6. The within groups variance was calculated as 3. What is the calculated value of the between groups variance?

A) 3
B) 2
C) 18
D) 9

Question 5

You have calculated a t statistic of 2.5. The between groups variance was calculated as 10. What is the calculated value of the within groups variance?

A) 12.5
B) 4
C) 7.5
D) 5

Question 6

In the t equation, how is the top half of the equation calculated?

A) By subtracting the mean in one condition from the mean in the other condition
B) By adding the mean in one condition to the mean in the other condition
C) By multiplying the mean in one condition by the mean in the other condition
D) By dividing the mean in one condition by the mean in the other condition

Question 7

You run a study where there are 35 participants in one condition and 40 participants in the other. How many degrees of freedom would you have?

A) 75
B) 34
C) 73
D) 39

Question 8

You run a study where there are 12 participants in one condition and 15 participants in the other. How many degrees of freedom would you have?

A) 27
B) 25
C) 11
D) 14

Question 9

You calculate a t test where you have a two-tailed hypothesis, 5 degrees of freedom and an alpha level of .050. What is the critical value for this analysis?

A) 2.015
B) 4.032
C) 3.182
D) 2.571

Question 10

Which of the following is the correct way to report a t test?

A) t = (10) 3.18, p < .010
B) t (10) = 3.18, p .010
C) t (10) = 3.18, p < .010
D) p < .010, t (10) = 3.18

Question 11

What is the mean for the "no mental health history" group?

A) 3.17
B) 7.0
C) 19
D) 75

Question 12

What is the sum of the raw scores (Σx₂) for the "mental health history" group?

A) 75
B) 19
C) 322
D) 42

Question 13

What is the value calculated for the top part of the t equation?

A) 3.83
B) -3.83
C) 1.196
D) -1.96

Question 14

What is the value on the lower part of the equation that requires a square root calculation?

A) -3.83
B) 0.334
C) 4.2833
D) 1.431

Question 15

What is the calculated t value?

A) -3.20
B) 1.196
C) -3.83
D) 3.169