Question 1

A type II error occurs when a researcher says an effect ______ when it in fact ______.

Accepted Answer

A)  exists; does 
B)  exists; does not 
C)  does not exist; does 
D)  does not exist; does not 
A)  exists; does 
B)  exists; does not 
C)  does not exist; does 
D)  does not exist; does not

Question 2

Which of the following would be considered a 'large' effect size according to Cohen?

Accepted Answer

A)  r2 = .21 
B)  r2 = .02 
C)  r2 = .05 
D)  r2 = .12 
A)  r2 = .21 
B)  r2 = .02 
C)  r2 = .05 
D)  r2 = .12

Question 3

Which of these strategies is most commonly used to reduce the probability of type II error?

Accepted Answer

A)  use a non-directional (two-tailed) instead of a directional (one-tailed) alternative hypothesis 
B)  never conclude an effect exists regardless of the evidence 
C)  increase sample size 
D)  lower alpha 
A)  use a non-directional (two-tailed) instead of a directional (one-tailed) alternative hypothesis 
B)  never conclude an effect exists regardless of the evidence 
C)  increase sample size 
D)  lower alpha

Question 4

An r2 = .01 is considered a 'large' effect size according to Cohen.

Accepted Answer

A) True 
 B)False

Question 5

Which statistic is an estimate of the magnitude of the difference between the means of two groups measured in standard deviation units?

Accepted Answer

A)  r2 
B)  t2 
C)  Cohen's d 
D)  β 
A)  r2 
B)  t2 
C)  Cohen's d 
D)  β

Question 6

One way to reduce the probability of making a type I error is to ______.

Accepted Answer

A)  make it easier to reject the null hypothesis 
B)  increase sample size 
C)  increase alpha 
D)  lower alpha 
A)  make it easier to reject the null hypothesis 
B)  increase sample size 
C)  increase alpha 
D)  lower alpha

Question 7

Which of these strategies is MOST commonly used to decrease type I error?

Accepted Answer

A)  using a directional alternative hypothesis 
B)  lowering alpha 
C)  increasing sample size 
D)  increasing alpha 
A)  using a directional alternative hypothesis 
B)  lowering alpha 
C)  increasing sample size 
D)  increasing alpha

Question 8

A type I error only affects the research community.

Accepted Answer

A) True 
 B)False

Question 9

The probability of making a type II error is ______.

Accepted Answer

A)  .05 
B)  1 - α 
C)  .95 
D)  none of these 
A)  .05 
B)  1 - α 
C)  .95 
D)  none of these

Question 10

How could a researcher interpret an r2 value of .35?

Accepted Answer

A)  .35% of the variance in one variable is explained by another variable. 
B)  3.5% of the variance in one variable is explained by another variable. 
C)  35% of the variance in one variable is explained by another variable. 
D)  65% of the variance in one variable is explained by another variable. 
A)  .35% of the variance in one variable is explained by another variable. 
B)  3.5% of the variance in one variable is explained by another variable. 
C)  35% of the variance in one variable is explained by another variable. 
D)  65% of the variance in one variable is explained by another variable.

Question 11

When the within-group variability in a study is small, the likelihood of rejecting the null hypothesis is ______.

Accepted Answer

A)  smaller 
B)  not changed 
C)  larger 
D)  the same 
A)  smaller 
B)  not changed 
C)  larger 
D)  the same

Question 12

For which of these strategies used to reduce the probability of type II error are pragmatic concerns such as time and cost most relevant?

Accepted Answer

A)  using a directional (one-tailed) rather than non-directional (two-tailed) alternative hypothesis 
B)  increasing sample size 
C)  making it harder to reject the null hypothesis 
D)  changing alpha 
A)  using a directional (one-tailed) rather than non-directional (two-tailed) alternative hypothesis 
B)  increasing sample size 
C)  making it harder to reject the null hypothesis 
D)  changing alpha

Question 13

Type I errors occur as the result of chance factors.

Accepted Answer

A) True 
 B)False

Question 14

In airport security screening, ______ errors occur when the screening device ______ when in fact ______.

Accepted Answer

A)  type I; beeps; it should not 
B)  type I; does not beep; it should 
C)  type II; beeps; it should not 
D)  type II; beeps; it should 
A)  type I; beeps; it should not 
B)  type I; does not beep; it should 
C)  type II; beeps; it should not 
D)  type II; beeps; it should

Question 15

Calculate the r2 statistic for t = 2.56 and two groups of 20 individuals each.

Accepted Answer

A)  .06 
B)  .15 
C)  .25 
D)  .27 
A)  .06 
B)  .15 
C)  .25 
D)  .27

Question 16

A type II error means that a researcher has ______.

Accepted Answer

A)  correctly concluded that an effect does not exist 
B)  correctly concluded that an effect exists 
C)  falsely concluded that an effect does not exist 
D)  falsely concluded that an effect exists 
A)  correctly concluded that an effect does not exist 
B)  correctly concluded that an effect exists 
C)  falsely concluded that an effect does not exist 
D)  falsely concluded that an effect exists

Question 17

An r2 = .86 is considered a 'large' effect size according to Cohen.

Accepted Answer

A) True 
 B)False

Question 18

Which of these strategies is MOST commonly used to decrease type II error?

Accepted Answer

A)  using a non-directional (two-tailed) alternative hypothesis (H1) 
B)  using a directional (one-tailed) null hypothesis (H0) 
C)  increasing sample size 
D)  lowering alpha 
A)  using a non-directional (two-tailed) alternative hypothesis (H1) 
B)  using a directional (one-tailed) null hypothesis (H0) 
C)  increasing sample size 
D)  lowering alpha

Question 19

A type I error occurs when researchers make the decision to ______ when they ______.

Accepted Answer

A)  reject the null hypothesis; should 
B)  reject the null hypothesis; should not 
C)  reject the alternative hypothesis; should not 
D)  not reject the null hypothesis; should not 
A)  reject the null hypothesis; should 
B)  reject the null hypothesis; should not 
C)  reject the alternative hypothesis; should not 
D)  not reject the null hypothesis; should not

Question 20

The probability of making a ______ error is equal to ______.

Accepted Answer

A)  type I; 1 - β 
B)  type II; 0 
C)  type II; α 
D)  type II; β 
A)  type I; 1 - β 
B)  type II; 0 
C)  type II; α 
D)  type II; β

A type II error occurs when a researcher says an effect when it in fact .

Which of the following would be considered a 'large' effect size according to Cohen?

Which of these strategies is most commonly used to reduce the probability of type II error?

An r² = .01 is considered a 'large' effect size according to Cohen.

Which statistic is an estimate of the magnitude of the difference between the means of two groups measured in standard deviation units?

One way to reduce the probability of making a type I error is to ______.

Which of these strategies is MOST commonly used to decrease type I error?

A type I error only affects the research community.

The probability of making a type II error is ______.

How could a researcher interpret an r² value of .35?

When the within-group variability in a study is small, the likelihood of rejecting the null hypothesis is ______.

For which of these strategies used to reduce the probability of type II error are pragmatic concerns such as time and cost most relevant?

Type I errors occur as the result of chance factors.

In airport security screening, errors occur when the screening device when in fact __.

Calculate the r² statistic for t = 2.56 and two groups of 20 individuals each.

A type II error means that a researcher has ______.

An r² = .86 is considered a 'large' effect size according to Cohen.

Which of these strategies is MOST commonly used to decrease type II error?

A type I error occurs when researchers make the decision to when they .

The probability of making a error is equal to .

Introduction to Statistics

Examining Data: Tables and Figures

Measures of Central Tendency

Measures of Variability

Normal Distributions

Probability and Hypothesis Testing

Testing One Sample Mean

Estimating the Mean of a Population

Testing the Difference Between Two Means

One-Way Analysis of Variance Anova

Two-Way Analysis of Variance Anova

Correlation

Linear Regression and Multiple Correlation

Chi-Square

Filters

Exam 10: Errors in Hypothesis Testing, Statistical Power, and Effect Size

A type II error occurs when a researcher says an effect ______ when it in fact ______.

Which of the following would be considered a 'large' effect size according to Cohen?

Which of these strategies is most commonly used to reduce the probability of type II error?

An r2 = .01 is considered a 'large' effect size according to Cohen.

Which statistic is an estimate of the magnitude of the difference between the means of two groups measured in standard deviation units?

One way to reduce the probability of making a type I error is to ______.

Which of these strategies is MOST commonly used to decrease type I error?

A type I error only affects the research community.

The probability of making a type II error is ______.

How could a researcher interpret an r2 value of .35?

When the within-group variability in a study is small, the likelihood of rejecting the null hypothesis is ______.

For which of these strategies used to reduce the probability of type II error are pragmatic concerns such as time and cost most relevant?

Type I errors occur as the result of chance factors.

In airport security screening, ______ errors occur when the screening device ______ when in fact ______.

Calculate the r2 statistic for t = 2.56 and two groups of 20 individuals each.

A type II error means that a researcher has ______.

An r2 = .86 is considered a 'large' effect size according to Cohen.

Which of these strategies is MOST commonly used to decrease type II error?

A type I error occurs when researchers make the decision to ______ when they ______.

The probability of making a ______ error is equal to ______.

Introduction to Statistics

Examining Data: Tables and Figures

Measures of Central Tendency

Measures of Variability

Normal Distributions

Probability and Hypothesis Testing

Testing One Sample Mean

Estimating the Mean of a Population

Testing the Difference Between Two Means

One-Way Analysis of Variance Anova

Two-Way Analysis of Variance Anova

Correlation

Linear Regression and Multiple Correlation

Chi-Square

Filters

A type II error occurs when a researcher says an effect when it in fact .

An r² = .01 is considered a 'large' effect size according to Cohen.

How could a researcher interpret an r² value of .35?

In airport security screening, errors occur when the screening device when in fact __.

Calculate the r² statistic for t = 2.56 and two groups of 20 individuals each.

An r² = .86 is considered a 'large' effect size according to Cohen.

A type I error occurs when researchers make the decision to when they .

The probability of making a error is equal to .