Deck 7: Independent Variables and Validity in Research

Question 1

The ________ measure of variability indicates the average difference between the scores of a distribution and the mean of a distribution.

A) range
B) standard deviation
C) mode
D) median

Answer 1

standard deviation

Question 2

If we retain the null hypothesis when it's really false, we have made a

A) correct decision.
B) Type I error.
C) Type II error.
D) none of the above.

Answer 2

Type II error.

Question 3

An inferential test allows a researcher to certain that there is or is not an effect of an independent variable.

A) true
B) false

Answer 3

false

Question 4

________ statistics summarize a distribution, while _______ statistics provide a test of the hypothesis.

A) central; variability
B) variability; central
C) inferential; descriptive
D) descriptive; inferential
(e) none of the above fit the sentence

Question 5

One way that researchers sometimes estimate the population mean from the sample mean is with a confidence interval.

Question 6

The calculated average of the scores in a distribution is the

A) range
B) mean
C) mode
D) median

Question 7

In inferential statistics, we look for evidence against the

A) alternative hypothesis.
B) scientific hypothesis.
C) independent variable hypothesis.
D) null hypothesis.

Question 8

A(n) ________ hypothesis predicts a directional effect, whereas a(n) _________ hypothesis predicts an effect in either direction.

A) one-tailed, two-tailed
B) two-tailed, one-tailed
C) null, alternative
D) alternative, null

Question 9

The middle score in a distribution, such that half of the scores are above and half are below that value is the

A) range
B) mean
C) mode
D) median

Question 10

A(n) ________ hypothesis predicts no effect, whereas a(n) _________ hypothesis predicts an effect.

A) one-tailed, two-tailed
B) two-tailed, one-tailed
C) null, alternative
D) alternative, null

Question 11

Extreme high or low scores in a distribution are referred to as

A) outliers
B) extremes
C) edges
D) limits

Question 12

The value of an inferential statistic calculated to compare conditions in an experiment represents

A) the chance that the null hypothesis is true.
B) the chance that the null hypothesis is false.
C) the effect of the independent variable with sampling error removed.
D) the amount of sampling error.

Question 13

Which of the following can explain the results of this study?

A) Exercise decreases memory abilities.
B) More subjects with better memory were assigned to the Sudoku group than the exercise group.
C) Subjects in the exercise group paid less attention to the study list than subjects in the Sudoku group.
D) All of the above.

Question 14

Two-tailed hypotheses are typically made only when a researcher has a logical reason to believe that one particular direction of the effect will occur.

Question 15

The most common score in a distribution is the

A) range
B) mean
C) mode
D) median

Question 16

If we reject the null hypothesis when it's really true, we have made a

A) correct decision.
B) Type I error.
C) Type II error.
D) none of the above.

Question 17

A distribution is (an)

A) descriptive statistic.
B) inferential statistic.
C) value that represents a typical score.
D) set of scores.
E) none of the above.

Question 18

The null hypothesis is the opposite hypothesis to the scientific or alternative hypothesis.

Question 19

A graph of the means for different conditions in a study where the bar height represents the size of the mean is a bar graph.

Question 20

The difference between the highest and lowest scores in a distribution is the:

A) range
B) mean
C) mode
D) median

Question 21

What does the p value in an inferential test represent?

Question 22

A researcher is conducting a study to test the hypothesis that viewing family photos as compared with viewing photos of strangers) prompts more autobiographical memories. State the null and alternative hypotheses for this study.

Question 23

The critical region is the most extreme portion of a distribution of statistical values for the null hypothesis determined by the alpha level.

Question 24

For the study above, suppose the test to compare the conditions resulted in a p value of .037. What decision should the researcher make in this case?

Question 25

A Type II Error is an error made in a significance test when the researcher fails to reject the null hypothesis when it is actually false.

Question 26

A graph of the means for different conditions in a study where each mean is graphed as a point and the points are connected in a line to show differences between mean scores is a line graph.

Question 27

A Type II Error is an error made in a significance test when the researcher rejects the null hypothesis when it is actually true.

Question 28

If the p value is more than alpha, the test is said to be significant.

Question 29

Explain why it is necessary to set an alpha level of an inferential test.

Question 30

The distribution of sample means is used to determine how likely it is that any sample mean will occur for a population.