Question 1

If the null hypothesis of an experiment is true

Accepted Answer

If the null hypothesis is true, it assumes that there is no difference between the conditions being tested. Therefore, the means of each condition would be essentially the same.

Question 2

Chance can affect the data in an experiment

Accepted Answer

Chance can affect the data in an experiment by producing differences between the means of the conditions. This means that the data from each group may vary due to chance, leading to differences in the overall mean between groups. This is why statistical tests are necessary to determine if the differences observed are statistically significant or simply due to chance. A and C are incorrect because the choice of statistics and variability levels can also be affected by chance. D is incorrect because chance does not reduce variability.

Question 3

The sum of squares is actually

Accepted Answer

The sum of squares is a statistical tool used to measure the variability of the data. It calculates the sum of the squared differences between each data point and the mean, and is used to determine the variance and standard deviation of a dataset. A Type l error refers to rejecting a true null hypothesis, while a Type ll error refers to failing to reject a false null hypothesis - neither of which are related to the sum of squares. The sum of squares is also not a measure of the validity of the data, as validity refers to whether a measurement tool is accurately measuring what it is intended to measure.

Question 4

If the variability between conditions is larger than the variability within conditions,

Accepted Answer

If the variability between conditions is larger than the variability within conditions, it indicates that the groups being compared are different from each other. This results in a larger F-ratio (between-group variability/within-group variability) than 1, indicating statistical significance. Therefore, choice B is the correct answer.

Question 5

Dr. Bryant gave 40 people a story to read that evoked one of four emotions sad, happy, angry, neutral) then evaluated the number of words that they could remember in a short-term memory task. The degrees of freedom associated with the between-conditions variability for this experiment would be

Accepted Answer

The degrees of freedom associated with the between-conditions variability is equal to the number of conditions minus one. In this experiment, there are four conditions (sad, happy, angry, neutral), so the degrees of freedom would be 4-1=3.

Question 6

No matter what the design of the experiment, an ANOVA table will always contain

Accepted Answer

An ANOVA table will always contain a row for each source of variance, which includes the between-group variance and the within-group variance. It may also include a row for the total variance, but this is not always the case. The ANOVA table may or may not include an interaction term, depending on the design of the experiment. The standard deviation is not typically included in an ANOVA table, as it is a measure of variability rather than a source of variance. The ANOVA table may also include columns listing the degrees of freedom, sum of squares, mean square, F-value, p-value, and effect size, but these are not universal across all ANOVA tables.

Question 7

When there is no experimental effect

Accepted Answer

When there is no experimental effect, any observed differences in data are due to chance, meaning chance affects the data.

Question 8

All data sets contain a certain amount of

Accepted Answer

All data sets contain a certain amount of variability, which refers to the range of values within the data set. Type l and Type ll errors, as well as alpha, are all related to hypothesis testing and statistical significance, and are not inherent characteristics of a data set.

Question 9

In a one-way ANOVA

Accepted Answer

In a one-way ANOVA, there is only one independent variable, which is the primary characteristic that differentiates it from other types of ANOVA, such as two-way ANOVA, which involves two independent variables.

Question 10

The value of the F-ratio obtained in an experiment is evaluated against

Accepted Answer

The F-ratio obtained in an experiment is evaluated against the value of the F-ratio expected to occur by chance alone, which is determined by the degrees of freedom and the significance level of the test. This is the basis for conducting an analysis of variance (ANOVA) test. The F-ratio is calculated by dividing the between-group variance by the within-group variance, and the resulting value is compared to a critical value from an F-distribution table. If the calculated F-ratio is greater than the critical value, it is concluded that there is a statistically significant difference between at least two of the groups being compared. Therefore, the best choice is B.

Question 11

The variability in an experiment

Accepted Answer

Variability can occur both between groups and within the subjects of a group. Variability between groups is known as intergroup variability, while variability within subjects is known as intrasubject variability. Measuring both types of variability is important for understanding the results of an experiment.

Question 12

The ________ statistic tests whether the means of more than two groups are equal

Accepted Answer

ANOVA (Analysis of Variance) is the statistic used to test whether the means of more than two groups are different from each other. It compares the variability within the groups to the variability between the groups. If the variability between the groups is significantly greater than the variability within the groups, then we can conclude that at least one of the groups has a different mean than the others.

Question 13

Dr. Kurtz conducts an experiment to see if the odor of peppermint causes people to walk around a track more quickly than if they smell lavender or no odor at all. The null hypothesis would be that

Accepted Answer

The null hypothesis is the assumption that there is no significant difference between the groups being compared in the experiment. Therefore, the correct option is D, "There is no difference in the mean speeds of the three conditions."

Question 14

A One-Way ANOVA means that

Accepted Answer

A One-Way ANOVA is used when there is only one independent variable with multiple levels or groups to compare.

Question 15

If you look at an ANOVA table and see the word "subjects" in one of the rows, you know

Accepted Answer

The answer of If you look at an ANOVA table...

Quiz 15: Data Exploration, Part 2: Inferential Statistics