Deck 22: Inferential Data Analysis

Question 1

A .05 level of significance means that

A)there is only a 5% chance that the statistic's value could be obtained as a result of sampling errors only.
B) one is 50% certain that the sample value is representative of the population.
C) there is only a 5% chance that the variables tested are not independent.
D) the results can be accepted because the sampling error is only 5%.
E) the level of confidence is only 5%.

Answer 1

A

Question 2

In reference to sampling error,which of the following statements is valid?

A) The smaller the sample, the less sampling error.
B) Sampling error is an inverse function of sample size.
C) Inferential statistics are addressed to sampling and non-sampling errors.
D) Random assignment ensures no sampling error.

Answer 2

B

Question 3

The smaller the sample,the greater the probability of obtaining
statistically significanindings.

Answer 3

False

Question 4

A research article reports that clients who received Intervention A had a 20% recidivism rate,while clients who received Intervention B had a 30% recidivism rate.What can be inferred from these statistics?

A)Intervention A is more effective than Intervention B.
B) The difference in recidivism rates may have been due to chance.
C) We risk a Type II error if we conclude that Intervention A is more effective than Intervention B.
D) We risk a Type I error if we conclude that the difference in recidivism rates may have been due to chance.

Question 5

A relationship with a correlation of .50

A) has more substantive significance than any other relationship with a lower correlation.
B) shows that 50% of the variation in the dependent variable is explained.
C) is stronger than any relationship with a correlation of -.50.
D) is more likely to be statistically significant than any relationship with a lower correlation.
E)might not be substantively significant

Question 6

An experiment is conducted to test the effectiveness of a social work intervention.The experimental group improves more than does the control group,but the results are not statistically significant.This means that

A)the intervention was not effective.
B)the intervention was effective, but not at a significant level.
C)we cannot rule out sampling error in inferring about the effectiveness of the intervention.
D)the results were clinically significant despite not being statistically significant.

Question 7

A Cohen's d effect size of .60 is

A) stronger than the average Cohen's d effect size reported in meta-analyses in social work and allied fields.
B) weaker than the average Cohen's d effect size reported in meta-analyses in social work and allied fields.
C) about the same as the average Cohen's d effect size reported in meta-analyses in social work and allied fields.
D) substantively significant.
E)not substantively significant.

Question 8

Two-tailed tests of significance should be used whenever there is
a non-directional hypothesis.

Question 9

We commit a Type II error when we

A)accept a false null hypothesis.
B)accept a true null hypothesis.
C)reject a false null hypothesis.
D)reject a true null hypothesis

Question 10

When two groups are significantly different on a dependent variable at the .05 level of significance,it means that there is a
five-percent difference between them.

Question 11

When a finding is statistically significant:

A)alternative explanations other than the independent variable are not plausible.
B)a strong relationship has been observed.
C)it is an importaninding.
D)its meaning depends on the rigor of the research methods.

Question 12

Which of the following hypotheses assumes that there is no relationship between two variables?

A)Research
B)Null
C)Alternate
D)Secondary
E)Substantive

Question 13

When using inferential statistics,we must risk either a Type I error or a Type II error,we cannot avoid risking both.

Question 14

A researcher conducts a test of statistical significance and finds a probability of less than .05.The researcher should NOT conclude that

A)it is improbable that the observed relationship could have resulted from sampling error alone.
B)the null hypothesis was rejected.
C)there is a statistically significant relationship at the .05 level.
D)the results have important implications for social work.

Question 15

Inferential statistics are used primarily for describing samples.

Question 16

The selection of the significance level

A)is fixed at .05 for social science research.
B)depends on the size of the population.
C)is arbitrary, although .05 is frequently used.
D)must be decided after finishing the analysis.

Question 17

If a result is statistically significant,it is also substantively
significant.

Question 18

A correlation of .60 indicates that 36 percent of the variance in the dependent variable has been explained.

Question 19

A research article reports that 4 of 10 students who received an intervention from a school social worker dropped out of school,while 6 of 10 students in the control group dropped out.The difference was not statistically significant.What can be inferred from these statistics?

A)The social worker's intervention was not effective.
B) The social worker's intervention was effective, but just not at a statistically significant level.
C) The same difference in drop out rates with a much larger sample might be statistically significant.
D)The same difference in drop out rates with a smaller sample might be statistically significant.

Question 20

In an evaluation of an intervention that seeks to reduce depression scores among the frail elderly,the mean of the experimental group is 30,the mean of the control group is 60,and the standard deviation is 10.Cohen's d effect size is

A) 3
B) minus 3
C) 30
D) 10

Question 21

Interpret the meaning of an odds ratio finding in which 80 percent of Intervention A recipients had a successful outcome,and 50 percent of Treatment As Usual recipients had a successful outcome.

Question 22

Explain the difference between statistical significance,relationship strength,and substantive significance.

Question 23

The more statistically significant a finding,the less likely it is
to be explained away by extraneous variables or design flaws.

Question 24

Mathematics dictates that all tests of statistical significance should use .05 as the significance level.

Question 25

If a Cohen's d effect size exceeds .6,the finding is statistically significant.

Question 26

Explain Type I and Type 11 errors,when they are risked,and what can be done to reduce their risks.

Question 27

The odds ratio shows how much more or less likely a certain dependent variable outcome is for categories of the independent variable

Question 28

Risk ratios show the proportion of unsuccessful outcomes in one group divided by the risk of unsuccessful outcomes in the other group

Question 29

The number needed to treat calculation bears upon the practical value of the risk ratio

Question 30

How would you interpret a finding from an experiment in which a costly and time-consuming intervention to reduce school dropout had a statistically significant outcome with a Cohen's d effect size of .20? What if the effect size were .80,but the outcome were not statistically significant due to a low sample size?