Question 1

Cohen's d measures effect sizes in terms of:

Accepted Answer

A)  standard deviation. 
B)  standard error. 
C)  sum of squared error. 
D)  sample size. 
A)  standard deviation. 
B)  standard error. 
C)  sum of squared error. 
D)  sample size.

Question 2

The formula for Cohen's d substitutes the _____ symbol for the _____ symbol used in the denominator of the z statistic formula.

Accepted Answer

A)  $\sigma $M; $\mu  $ 
B)  $\sigma $; $\sigma $M 
C)  $\mu  $M; $\mu  $ 
D)  $\mu  $; $\sigma $M 
A)  $\sigma $M; $\mu  $ 
B)  $\sigma $; $\sigma $M 
C)  $\mu  $M; $\mu  $ 
D)  $\mu  $; $\sigma $M

Question 3

Which of the following is NOT a way to resolve issues with the file drawer problem?

Accepted Answer

A)  replicating a study 
B)  evaluating publication bias 
C)  conducting a file drawer analysis 
D)  eliminating unpublished studies from analysis 
A)  replicating a study 
B)  evaluating publication bias 
C)  conducting a file drawer analysis 
D)  eliminating unpublished studies from analysis

Question 4

When alpha increases, both _____ and _____ increase.

Accepted Answer

A)  standard error; power 
B)  power; probability of a Type I error 
C)  power; probability of a Type II error 
D)  probability of a Type I error; probability of a Type II error 
A)  standard error; power 
B)  power; probability of a Type I error 
C)  power; probability of a Type II error 
D)  probability of a Type I error; probability of a Type II error

Question 5

A Cohen's d value of 0.5 indicates what effect size?

Accepted Answer

A)  small 
B)  medium 
C)  large 
D)  no effect 
A)  small 
B)  medium 
C)  large 
D)  no effect

Question 6

Michelle is a cognitive psychologist studying reading times for stories that contain either consistent or inconsistent information.She runs 38 people through her study and concludes that reading times slow when coherence breaks occur in a story.Specifically, she concludes reading times slow by 6.9 milliseconds on average.Michelle's prediction is a(n):

Accepted Answer

A)  interval estimate. 
B)  standard deviation. 
C)  point estimate. 
D)  sigma score. 
A)  interval estimate. 
B)  standard deviation. 
C)  point estimate. 
D)  sigma score.

Question 7

An interval estimate is based on a population parameter and provides a range of plausible values for the sample statistic.

Accepted Answer

A) True 
 B)False

Question 8

Recent research published by Frumin and colleagues (2011) in the journal Science addresses whether females' tears have an effect on males.Imagine that exposure to tears lowered self-rated sexual arousal by 1.27 points, with a margin of error of 0.32 points.The point estimate is _____, while the interval estimate is _____.

Accepted Answer

A)  0.32; [0.95, 1.59] 
B)  1.27; [0.95, 1.59] 
C)  0.32; [-0.95, 1.59] 
D)  1.27; [-0.95, 1.59] 
A)  0.32; [0.95, 1.59] 
B)  1.27; [0.95, 1.59] 
C)  0.32; [-0.95, 1.59] 
D)  1.27; [-0.95, 1.59]

Question 9

A researcher is comparing the normal curve for two studies using the standard deviation for individual scores.Study 1 depicts two samples with means close together, while the means in Study 2 are farther apart.Which has a bigger effect size?

Accepted Answer

A)  Study 1 because there is more overlap between distributions 
B)  Study 1 because there is less overlap between distributions 
C)  Study 2 because there is more overlap between distributions 
D)  Study 2 because there is less overlap between distributions 
A)  Study 1 because there is more overlap between distributions 
B)  Study 1 because there is less overlap between distributions 
C)  Study 2 because there is more overlap between distributions 
D)  Study 2 because there is less overlap between distributions

Question 10

A Cohen's d of -0.85 is what type of effect size?

Accepted Answer

A)  large 
B)  medium 
C)  small 
D)  Because it is less than zero, there is no effect. 
A)  large 
B)  medium 
C)  small 
D)  Because it is less than zero, there is no effect.

Question 11

Statistical power is a measure of the ability to retain the null hypothesis when it is true.

Accepted Answer

A) True 
 B)False

Question 12

The larger the effect size, the:

Accepted Answer

A)  smaller is the test statistic. 
B)  smaller is the sample size. 
C)  more two distributions overlap. 
D)  less two distributions overlap. 
A)  smaller is the test statistic. 
B)  smaller is the sample size. 
C)  more two distributions overlap. 
D)  less two distributions overlap.

Question 13

Alpha refers to:

Accepted Answer

A)  statistical power. 
B)  the probability of making a Type II error. 
C)  the probability of making a Type I error. 
D)  effect size. 
A)  statistical power. 
B)  the probability of making a Type II error. 
C)  the probability of making a Type I error. 
D)  effect size.

Question 14

As N increases, the width of the confidence interval increases.

Accepted Answer

A) True 
 B)False

Question 15

The critical cutoffs for a 95 percent confidence interval are -1.96 and 1.96.What are the cutoffs for a 90 percent confidence interval?

Accepted Answer

A)  -1.65 and 1.65 
B)  -1.76 and 1.76 
C)  -1.96 and 1.96 
D)  -2.12 and 2.12 
A)  -1.65 and 1.65 
B)  -1.76 and 1.76 
C)  -1.96 and 1.96 
D)  -2.12 and 2.12

Question 16

As effect size increases, the overlap between distributions being compared:

Accepted Answer

A)  increases. 
B)  decreases. 
C)  remains the same. 
D)  Overlap is not compared for distributions. 
A)  increases. 
B)  decreases. 
C)  remains the same. 
D)  Overlap is not compared for distributions.

Question 17

The amount of overlap between two distributions can be decreased if their means are further apart.

Accepted Answer

A) True 
 B)False

Question 18

An article in the journal Applied Nutritional Investigation reported the results of a comparison between a low-calorie soy-protein diet and a low-calorie traditional-protein diet (Liao, 2007).Twelve obese participants were randomly assigned to each diet.At the end of the diet period, those on the soy diet lost an average of 2.3 percent of their body fat (SD = 0.55), while those on the traditional diet lost an average of 1.22 percent of their body fat (SD = 0.50).If the sample size of this study is increased, the value of the test statistic would _____ and the effect size would _____.

Accepted Answer

A)  increase; remain the same 
B)  decrease; remain the same 
C)  decrease; increase 
D)  increase; decrease 
A)  increase; remain the same 
B)  decrease; remain the same 
C)  decrease; increase 
D)  increase; decrease

Question 19

According to the video game industry's statistics, the average gamer is 34 years old.Imagine the standard deviation for age is 7.5 years.Leroy collected data on video gaming among people with new tablets or iPads to see if the mean age of that group is older or younger.He finds an average age of 36.5 years based on a sample size of 54.His 95 percent confidence interval is:

Accepted Answer

A)  [34.58, 38.42]. 
B)  [36.23, 36.77]. 
C)  [33.88, 38.12]. 
D)  [34.5, 38.5]. 
A)  [34.58, 38.42]. 
B)  [36.23, 36.77]. 
C)  [33.88, 38.12]. 
D)  [34.5, 38.5].

Question 20

If a researcher performs a meta-analysis and finds that the mean d = 0.11, and that the 95 percent confidence interval around this mean is (-0.04, 0.26), what could the researcher conclude?

Accepted Answer

A)  All future studies of this effect will find effect sizes somewhere between 0.34 and 0.56. 
B)  Averaging across all of the literature, there really is no effect. 
C)  There is a strong effect, but it is unclear what the direction of the effect is. 
D)  Averaging across all of the literature, there is a strong effect, and this effect is statistically significant. 
A)  All future studies of this effect will find effect sizes somewhere between 0.34 and 0.56. 
B)  Averaging across all of the literature, there really is no effect. 
C)  There is a strong effect, but it is unclear what the direction of the effect is. 
D)  Averaging across all of the literature, there is a strong effect, and this effect is statistically significant.

Cohen's d measures effect sizes in terms of:

The formula for Cohen's d substitutes the _ symbol for the _ symbol used in the denominator of the z statistic formula.

Which of the following is NOT a way to resolve issues with the file drawer problem?

When alpha increases, both _ and _ increase.

A Cohen's d value of 0.5 indicates what effect size?

An interval estimate is based on a population parameter and provides a range of plausible values for the sample statistic.

A researcher is comparing the normal curve for two studies using the standard deviation for individual scores.Study 1 depicts two samples with means close together, while the means in Study 2 are farther apart.Which has a bigger effect size?

A Cohen's d of -0.85 is what type of effect size?

Statistical power is a measure of the ability to retain the null hypothesis when it is true.

The larger the effect size, the:

Alpha refers to:

As N increases, the width of the confidence interval increases.

The critical cutoffs for a 95 percent confidence interval are -1.96 and 1.96.What are the cutoffs for a 90 percent confidence interval?

As effect size increases, the overlap between distributions being compared:

The amount of overlap between two distributions can be decreased if their means are further apart.

If a researcher performs a meta-analysis and finds that the mean d = 0.11, and that the 95 percent confidence interval around this mean is (-0.04, 0.26), what could the researcher conclude?

An Introduction to Statistics and Research Design

Frequency Distributions

Visual Displays of Data

Central Tendency and Variability

Sampling and Probability

The Normal Curve, Standardization and Z Scores

Hypothesis Testing With Z Tests

The Single-Sample T Test

The Paired-Samples T Test

The Independent-Samples T Test

One-Way Between-Groups Anova

One-Way Within-Groups Anova

Two-Way Between-Groups Anova

Correlation

Regression

Chi-Square Tess

Choosing and Reporting Statistics

Filters

Exam 8: Confidence Intervals, Effect Size, and Statistical Power

Cohen's d measures effect sizes in terms of:

The formula for Cohen's d substitutes the _____ symbol for the _____ symbol used in the denominator of the z statistic formula.

Which of the following is NOT a way to resolve issues with the file drawer problem?

When alpha increases, both _____ and _____ increase.

A Cohen's d value of 0.5 indicates what effect size?

An interval estimate is based on a population parameter and provides a range of plausible values for the sample statistic.

A researcher is comparing the normal curve for two studies using the standard deviation for individual scores.Study 1 depicts two samples with means close together, while the means in Study 2 are farther apart.Which has a bigger effect size?

A Cohen's d of -0.85 is what type of effect size?

Statistical power is a measure of the ability to retain the null hypothesis when it is true.

The larger the effect size, the:

Alpha refers to:

As N increases, the width of the confidence interval increases.

The critical cutoffs for a 95 percent confidence interval are -1.96 and 1.96.What are the cutoffs for a 90 percent confidence interval?

As effect size increases, the overlap between distributions being compared:

The amount of overlap between two distributions can be decreased if their means are further apart.

If a researcher performs a meta-analysis and finds that the mean d = 0.11, and that the 95 percent confidence interval around this mean is (-0.04, 0.26), what could the researcher conclude?

An Introduction to Statistics and Research Design

Frequency Distributions

Visual Displays of Data

Central Tendency and Variability

Sampling and Probability

The Normal Curve, Standardization and Z Scores

Hypothesis Testing With Z Tests

The Single-Sample T Test

The Paired-Samples T Test

The Independent-Samples T Test

One-Way Between-Groups Anova

One-Way Within-Groups Anova

Two-Way Between-Groups Anova

Correlation

Regression

Chi-Square Tess

Choosing and Reporting Statistics

Filters

The formula for Cohen's d substitutes the _ symbol for the _ symbol used in the denominator of the z statistic formula.

When alpha increases, both _ and _ increase.