Question 1

1) Usually a researcher would prefer a result significant with:&#10;A) p < .01&#10;B) p < .1&#10;C) p < .05&#10;D) p < .5

Accepted Answer

A p-value of less than .01 indicates a stronger level of statistical significance, suggesting that the observed results are less likely to be due to random chance.

Question 2

2) Which of these is a null hypothesis:&#10;A) There will be no difference between males and females in number of problems solved&#10;B) There will be a difference between males and females in number of problems solved&#10;C) There is no difference between males and females in number of problems solved&#10;D) There is a difference between males and females in number of problems solved

Accepted Answer

The null hypothesis states that there is no difference between the two groups being compared. In this case, the null hypothesis would be "There is no difference between males and females in number of problems solved". Therefore, the correct answer is C.

Question 3

3) Which of the following is correct?&#10;A) In a one-tailed test the direction of the difference between groups is predicted&#10;B) In a one-tailed test the direction of the difference between groups is not predicted&#10;C) In a one-tailed test the alternative hypothesis does not state the predicted direction of difference between groups&#10;D) In a one-tailed test the null hypothesis predicts that there will be no difference between groups

Accepted Answer

In a one-tailed test, the direction of the difference between groups is predicted in the alternative hypothesis. The null hypothesis predicts no significant difference between groups. Therefore, option A is correct.

Question 4

4) In a normal distribution a z score of 2.55 would be:&#10;A) Significant with p < .05 two-tailed&#10;B) Significant with p < .01 two-tailed&#10;C) Significant with p < .001 one-tailed&#10;D) Significant with p < .005 one-tailed

Accepted Answer

A z-score of 2.55 falls within the range of approximately 0.99% of the area under the normal distribution curve. The alpha level corresponding to a one-tailed test would be 0.01, and for a two-tailed test, it would be 0.025. As 0.99% is larger than 0.025 but less than 0.01, the correct answer would be B, significant with p < .01 two-tailed.

Question 5

5) &#34;Girls will have higher math scores than boys&#34; is a:&#10;A) Non- directional hypothesis&#10;B) Directional hypothesis&#10;C) Non- directional prediction&#10;D) Directional prediction

Accepted Answer

The answer of 5) &#34;Girls will have higher math scores...

Question 6

6) A researcher using a 1% rather than a 5% level of significance is:&#10;A) More likely to make a Type I error&#10;B) More likely to make a Type II error&#10;C) Less likely to make a Type II error&#10;D) More likely to make both a Type I and Type II error

Accepted Answer

Using a 1% level of significance (compared to a 5% level) makes the criteria for rejecting the null hypothesis more stringent. This reduces the chance of incorrectly rejecting a true null hypothesis (Type I error) but increases the chance of failing to reject a false null hypothesis (Type II error).

Question 7

In a study which compares reaction times between two groups, one which has been asked to run a treadmill for 15 minutes and one not using the treadmill,
-8) In the above reaction time study, a difference between two groups in favour of the treadmill condition where p is less than .05 would indicate:

A) Proof that running a treadmill reduces reaction times
B) Support for the null hypothesis
C) Support for the proposal that running a treadmill reduces reaction times
D) That the alternative hypothesis should be rejected

Accepted Answer

Effect size is the estimated size of the difference between means of the populations from which the groups are drawn. It is a measure of the magnitude of the difference between the two groups, independent of sample size. It is not the actual size of the mean of either group or the difference between standard deviations.

Question 8

In a study which compares reaction times between two groups, one which has been asked to run a treadmill for 15 minutes and one not using the treadmill,
-8) In the above reaction time study, a difference between two groups in favour of the treadmill condition where p is less than .05 would indicate:

A) Proof that running a treadmill reduces reaction times
B) Support for the null hypothesis
C) Support for the proposal that running a treadmill reduces reaction times
D) That the alternative hypothesis should be rejected

Accepted Answer

A p-value less than .05 typically indicates statistical significance, suggesting evidence against the null hypothesis and in support of the alternative hypothesis, which in this context is that running on a treadmill reduces reaction times. It does not prove causality but supports the proposal.

Question 9

9) Suppose a friend said they could influence the fall of a coin and then proceeded to guess correctly on four consecutive tosses. We cannot accept this as a significant outcome because:&#10;A) The result of each toss is independent of the last result&#10;B) They did not formulate a null hypothesis&#10;C) The probability of four consecutive correct calls is greater than .05&#10;D) The coin could be biased

Accepted Answer

The answer of 9) Suppose a friend said they could...

Question 10

10) A researcher wishes to find out whether there is a significant difference between a group of South American students and a group of African students in liking for the course they have just finished. All students will leave the country permanently just after the survey is completed. An appropriate level of significance to achieve would be:

A) p < .01
B) p < .1
C) p < .05
D) p < .5

Accepted Answer

The answer of 10) A researcher wishes to find out...

Deck 16: Significance Testing Was It a Real Effect