Question 1

Which of the following statements is correct?

Accepted Answer

A)  More than one Pearson correlation coefficient can be calculated from the same scatterplot. 
B)  Only one Pearson correlation coefficient can be calculated from one scatterplot. 
C)  A scatterplot will show a higher relationship than the correlation coefficient calculated from it. 
D)  A scatterplot will show a lower relationship than the correlation coefficient calculated from it. 
A)  More than one Pearson correlation coefficient can be calculated from the same scatterplot. 
B)  Only one Pearson correlation coefficient can be calculated from one scatterplot. 
C)  A scatterplot will show a higher relationship than the correlation coefficient calculated from it. 
D)  A scatterplot will show a lower relationship than the correlation coefficient calculated from it. B

Question 2

In a study comparing class size to mathematics achievement, the unit of analysis is:

Accepted Answer

A)  the individual student 
B)  the class 
C)  the teacher 
D)  none of the above 
A)  the individual student 
B)  the class 
C)  the teacher 
D)  none of the above B

Question 3

Gain scores can be obtained by subtracting pretest scores from posttest scores.

Accepted Answer

A) True 
 B)False  True

Question 4

Scatterplots are recommended in addition to correlation coefficients because they:

Accepted Answer

A)  can correct errors in calculating 
B)  provide a pictorial rather than a numerical assessment 
C)  indicate which average should be used 
D)  provide more information 
A)  can correct errors in calculating 
B)  provide a pictorial rather than a numerical assessment 
C)  indicate which average should be used 
D)  provide more information

Question 5

Matching
-Straight-line relationship

Accepted Answer

A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender 
A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender

Question 6

Most researchers consider that any delta of .50 or larger is an important finding.

Accepted Answer

A) True 
 B)False

Question 7

Matching
-Effect size

Accepted Answer

A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender 
A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender

Question 8

If eta and r are in substantial disagreement:

Accepted Answer

A)  eta should be used 
B)  r should be used 
C)  neither should be used 
D)  an error in calculation has been made 
A)  eta should be used 
B)  r should be used 
C)  neither should be used 
D)  an error in calculation has been made

Question 9

In a comparison group study using two randomly selected groups, effect size = .24, and p<.01. This means the:

Accepted Answer

A)  difference in means is small and probably due to sampling error 
B)  difference in means is small but probably is not due to sampling error 
C)  difference in means is large enough to be important, but may well be due to sampling error 
D)  difference in means is large and probably not due to sampling error 
A)  difference in means is small and probably due to sampling error 
B)  difference in means is small but probably is not due to sampling error 
C)  difference in means is large enough to be important, but may well be due to sampling error 
D)  difference in means is large and probably not due to sampling error

Question 10

When random sampling was not used, probabilities obtained from inferential statistical procedures should:

Accepted Answer

A)  not be reported 
B)  be treated only as crude indices 
C)  be reported only if less than .01 
D)  be used as the primary index of the importance of results 
A)  not be reported 
B)  be treated only as crude indices 
C)  be reported only if less than .01 
D)  be used as the primary index of the importance of results

Question 11

Confidence intervals are recommended rather than significance tests because they:

Accepted Answer

A)  provide more information 
B)  are easier to calculate 
C)  require fewer mathematical assumptions 
D)  do not require as large a sample 
A)  provide more information 
B)  are easier to calculate 
C)  require fewer mathematical assumptions 
D)  do not require as large a sample

Question 12

A Pearson r of -.90 indicates a very weak relationship.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is not a danger in using inferential statistics to evaluate differences in averages?

Accepted Answer

A)  Important differences may be ignored. 
B)  Resulting probabilities are likely to be in error. 
C)  Complex calculations are likely to contain errors. 
D)  Large samples can make trivial differences appear important. 
A)  Important differences may be ignored. 
B)  Resulting probabilities are likely to be in error. 
C)  Complex calculations are likely to contain errors. 
D)  Large samples can make trivial differences appear important.

Question 14

Matching
-Quantitative variable

Accepted Answer

A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender 
A)  delta 
B)  Pearson r 
C)  eta. 
D)  IQ scores 
E)  gender

Question 15

When in doubt as to whether parametric or nonparametric statistics are appropriate, a researcher should:

Accepted Answer

A)  report only parametric statistics 
B)  report only nonparametric statistics 
C)  report both 
D)  use neither 
A)  report only parametric statistics 
B)  report only nonparametric statistics 
C)  report both 
D)  use neither

Question 16

The importance of a 15-point difference in means between two groups:

Accepted Answer

A)  depends on the spread of scores in each group 
B)  depends on the shape of the frequency polygons 
C)  depends on the number of cases in each group 
D)  all of the above 
A)  depends on the spread of scores in each group 
B)  depends on the shape of the frequency polygons 
C)  depends on the number of cases in each group 
D)  all of the above

Question 17

If inferential statistics are calculated, they should be obtained:

Accepted Answer

A)  as the first step in data analysis 
B)  as part of a comprehensive assessment of results 
C)  only after demonstration that the magnitude of the obtained relationship is worthy of attention 
D)  as part of the determination of effect size 
A)  as the first step in data analysis 
B)  as part of a comprehensive assessment of results 
C)  only after demonstration that the magnitude of the obtained relationship is worthy of attention 
D)  as part of the determination of effect size

Question 18

One commonly used index of effect size is obtained by:

Accepted Answer

A)  dividing the difference between means by the standard error of measurement 
B)  dividing the difference between means by the standard error of the mean 
C)  dividing the difference between means by the standard deviation of the control group 
D)  none of the above 
A)  dividing the difference between means by the standard error of measurement 
B)  dividing the difference between means by the standard error of the mean 
C)  dividing the difference between means by the standard deviation of the control group 
D)  none of the above

Question 19

In practice, most useful correlations between different variables are between:

Accepted Answer

A)  .00 and .30 
B)  .40 and .70 
C)  .70 and .90 
D)  over .90 
A)  .00 and .30 
B)  .40 and .70 
C)  .70 and .90 
D)  over .90

Question 20

A useful means of evaluating obtained differences among averages is by:

Accepted Answer

A)  comparison to averages of previously identified groups 
B)  examining the size of the groups 
C)  converting them to percentiles 
D)  calculating the magnitude of t 
A)  comparison to averages of previously identified groups 
B)  examining the size of the groups 
C)  converting them to percentiles 
D)  calculating the magnitude of t

Exam 12: Statistics in Perspective

Which of the following statements is correct?

In a study comparing class size to mathematics achievement, the unit of analysis is:

Gain scores can be obtained by subtracting pretest scores from posttest scores.

Scatterplots are recommended in addition to correlation coefficients because they:

Matching -Straight-line relationship

Most researchers consider that any delta of .50 or larger is an important finding.

Matching -Effect size

If eta and r are in substantial disagreement:

In a comparison group study using two randomly selected groups, effect size = .24, and p<.01. This means the:

When random sampling was not used, probabilities obtained from inferential statistical procedures should:

Confidence intervals are recommended rather than significance tests because they:

A Pearson r of -.90 indicates a very weak relationship.

Which of the following is not a danger in using inferential statistics to evaluate differences in averages?

Matching -Quantitative variable

When in doubt as to whether parametric or nonparametric statistics are appropriate, a researcher should:

The importance of a 15-point difference in means between two groups:

If inferential statistics are calculated, they should be obtained:

One commonly used index of effect size is obtained by:

In practice, most useful correlations between different variables are between:

A useful means of evaluating obtained differences among averages is by:

The Nature of Research

The Research Problem

Locating and Reviewing the Literature

Ethics and Research

Variables and Hypotheses

Sampling

Instrumentation

Validity and Reliability

Internal Validity

Descriptive Statistics

Inferential Statistics

Experimental Research

Single-Subject Research

Correlational Research

Causal-Comparative Research

Survey Research

The Nature of Qualitative Research

Observation and Interviewing

Content Analysis

Ethnographic Research

Historical Research

Mixed-Methods Research

Action Research

Preparing Research Proposals and Reports

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