Inferential Statistical Tests

Question 1

The selection of an inferential statistical test is based on several factors: The first factor is the ____ of ____ of the ____ to be ____. (When a study has independent and dependent variables, it is the measurement scale of the ____ ____ that is of interest since it is the data on the ____ ____ that will be ____ with the ____ ____.) The second factor is the ____ of the ____. Characteristics of the research design that determine which statistical test to use include the ____ of __ or, if there is only one IV, the ____ of its ____; whether the groups are ____ or ____; whether there are any ____ ____ that need to be ____; and the number of __.

Answer 1

Scale of Measurement; Data to be Analyzed; Dependent Variable; Dependent Variable; Analyzed; Statistical Test; Design of the Study; Number of IVs; Number of its Levels; Independent or Correlated; Extraneous Variables; Controlled; DVs

Question 2

____ ____ ____ ____: Inferential statistical tests are classified as ____ or ____. Use of both types of tests is based on the assumption that the sample has been ____ ____ from the ____. In addition, these tests assume that ____ are ____, which means that a subject’s participation in the study or performance on the DV is not affected by or related to the ____ or ____ of ____ ____ ____ (except, of course, to the extent that performance is due to the ____ of the __).

Answer 2

Parametric Versus Nonparametric Tests; Parametric or Nonparametric; Randomly Selected; Population; Observations are Independent; Participation or Performance of Any Other Subject; Effects of the IV

Question 3

Parametric and nonparametric tests differ in several important ways. ____ ____, which include the t-test and analysis of variance, are used to evaluate hypotheses about population means, variances, or other parameters. These tests are appropriate only when the variable of interest has been measured on an ____ or ____ ____ and when certain assumptions about the ____ ____ are met: The first assumption of is that the value of interest is ____ ____ in the ____. The second assumption is that, when a study includes more than one group, there is ____ that is, the variances of the populations that the different groups represent are equal. Violation of these assumptions — especially the assumption of ____ can increase the probability of making ____ ¬_ or ____ _ ¬____.

Answer 3

Parametric Tests; Interval or Ratio Scale; Population Distribution(s); Normally Distributed; Population; Homoscedasticity; Homoscedasticity; Type I or Type II Error

Question 4

The parametric tests are relatively “____” regarding ____ of their ____. which means that some deviation from a normal curve or from ____ will not necessarily ____ the ____ ____. The most effective way to maximize the robustness of a parametric test is to have an ____ ____ of ____ in ____ ____. Robustness is also increased by having a ____ ____ ____ and setting ____ at a ____ ____ (e.g., at .01 rather than .05).

Answer 4

Robust; Violation; Assumptions; Normal Curve; Homoscedasticity; Invalidate the Test’s Results; Equal Number of Subjects in Each Group; Large Sample Size; Alpha at a Lower Level

Question 5

The parametric tests are not as robust with regard to the assumption of ____ of ____, however: Even a small amount of dependence among observations can increase the probability of making a ____ _ ____ above the probability indicated by ____.

Answer 5

Independence of Observations; Type I Error; Alpha

Question 6

____ ____ are used to analyze data collected on variables that have been measured on a nominal or ordinal scale. These tests do not make the same assumptions about the ____ of the ____ ____, as the parametric tests and are referred to as ____-____ ____.

Answer 6

Nonparametric Tests; Shape or the Population Distribution(s); Distribution-Free Tests

Question 7

The nonparametric tests are used to evaluate hypotheses about the ____ of a ____ rather than the distribution’s mean, variance, or other parameter. Included in this category are the ____-____ ____, the ____-____ _ ____, and the ____ ____-____ ____, shortcoming of the nonparametric tests is that, because they involve using less precise (nominal or ordinal) data, they are less ____. In other words, a researcher is less likely to detect a ____ ________ with a nonparametric test than with a parametric one. For this reason, parametric tests are ____ ____ whenever they can be ____ used.

Answer 7

Shape of a Distribution; Chi-Square Tests; Mann-Whitney U Test; Wilcoxon Matched-Pairs Test; Powerful; False Null Hypothesis; Always Preferred; Legitimately

Question 8

When picking an inferential statistical test, the first thing you want to consider is the ____ of ____ of the ____ to be ____. (When the study has independent and dependent variables, it is the data on the __ that will be ____.) This will help you distinguish between the tests for ____, ____, and ____/____ ____. The next consideration is the ____ of the ____ ____ - i.e., the number of __ (or, for the chi-square test, the total number of ____); if one IV, the ____ of ____, the nature of the ____ (independent or correlated); the presence of ____ ____; and the number of __.

Answer 8

Scale of Measurement of the Data; DV; Analyzed; Nominal, Ordinal, and Interval/Ratio Data; Nature of the Research Design; IVs; Variables; Number of Levels; Groups; Extraneous Variables

Question 9

____ ____ and ____ of ____: Regardless of which inferential statistical test is used, its results yield a “____ ____” (_, _ etc.) that allows the investigator to determine whether the obtained sample value is in the ____ or ____ ____ of the ____ ____. This is done by comparing the ____ ____ to a ____ ____, which is the number that corresponds to the ____ that ____ the ____ ____ into ____ and ____ ____. Critical value tables are usually included in the appendices of statistics textbooks. For most statistical tests, when the ____ ____ ____ or ____ the ____ ____, this means that the sample value lies in the ____ ____; when the statistic is ____ ____ the ____ ____, the sample value is in the ____ ____.

Answer 9

Critical Values and Degrees of Freedom; “Test Statistic” (t, F); Rejection or Retention region; Sampling Distribution; Test Statistic to a Critical Value; Boundary that Divides the Sampling Distribution; Rejection and Retention Regions; Test Statistic Equals or Exceeds; Critical Value; Rejection Region; Less Than the Critical Value; Retention Region

Question 10

The magnitude of the critical value is determined by two factors: ____ and the ____ of ____. Alpha determines what proportion of the sampling distribution represents the ____ ____ and the degrees of freedom (df) determine the distribution’s exact ____. ____ of ____ are the number of values or categories in a distribution that are “free to vary” given that certain values or categories are known or fixed. To illustrate, assume that a sample mean is being used to estimate a population mean, and that the sample consists of eight test scores. The degrees of freedom in this example are 7 (8 - 1) since, once the sample mean is known, only 7 of the 8 scores are “free to vary”: If the sample mean is 50 and seven of the test scores are 80, 80, 70, 50, 40, 40, and 30, the 8th score is not free to vary. It must be 10 in order for the sample mean to be equal to 50.

Answer 10

Alpha; Degrees of Freedom; Rejection Region; Shape; Degrees of Freedom

Question 11

The method used to calculate degrees of freedom depends on the ____ ____. For the t-test for a single sample, the sampling distribution is based on the ____ ____; and the degrees of freedom are derived from the ____ ____ of ____ (_ - ). When using a single-sample chi-square test, a different kind of sampling distribution is used. It is based on the number of ____ (____) of the ____ and the degrees of freedom are derived from the ____ ____ of ____ ( - _).

Answer 11

Statistical Test; Sample Size; Total Number of Subjects (N - 1); Categories (Levels); Variable; Total Number of Categories (C – 1)

Question 12

The inferential statistical tests are categorized as parametric or nonparametric. Both types of tests share the assumptions that the sample has been (1) ____ from the population and that observations are (2) ____. A (3) ____ test is used when the data being analyzed represent a(n) (4) ____ or ratio scale of measurement and when two assumptions have been met. The first assumption is that, in the population from which the sample was drawn, scores on the variable are (5) ____ distributed. The second assumption is that there is “homoscedasticity,” which means that the (6) ____ of the populations that the different groups represent are equal.

Answer 12

(1) randomly selected; (2) independent; (3) parametric; (4) interval; (5) normally; (6) variances

Question 13

If the data to be analyzed do not meet the assumptions for a parametric test or if they represent a(n) (7) ____ or ordinal scale of measurement, a (8) ____ test is used. The major limitation of the nonparametric tests is that they are less (9) ____ than parametric tests, which means that, when using these tests, it is more difficult to detect a false (10) ____ hypothesis.

Answer 13

(7) nominal; (8) nonparametric; (9) powerful; (10) null

Question 14

Parametric and nonparametric tests both yield a test statistic that the researcher compares to a critical value, which is the cutoff point that divides the (11) ____ into the regions of likely and unlikely values. The critical value for a particular research study is determined by two factors: (12) ____ and the degrees of freedom.

Answer 14

(11) sampling distribution; (12) alpha

Question 15

The ____-____ ____ is used to analyze the frequency of observations in each category (level) of a nominal variable (or other variable that is being treated as a nominal variable). For example, the ____-___ ____ would be appropriate for comparing the number of people who prefer one of four political candidates or comparing the number of managerial and non-managerial employees who say that either physiological, safety, social, self-esteem, or self-actualization needs are most important.

Answer 15

Chi-Square Test; Chi-Square Test

Question 16

The chi-square test is used to determine if the ____ of____ (sample) ____ is ____ to the ____ of ____ ____. The expected frequencies are predicted by the ____ ____ and reflect either ____ ____ among the ____ or the known ____ in the ____. Use of the chi-square test not only requires the data to be reported in terms of ____ but also that the expected frequency for any one category is no less than ____ and that observations are ____ (i.e., each subject can appear in only ____ ____).

Answer 16

Distribution of Observed Frequencies is Equivalent to the Distribution of Expected Frequencies; Null Hypothesis; No Differences; Categories; Frequencies; Population; Frequencies; Five; Independent; One Category

Question 17

There are two forms of the chi-square test – the ____-____ and the ____-____. To help remember when each test is used, it’s better to think of them as the “____-____” and “____-____” ____-____ ____. The former is used when a study includes only ____ ____; the latter is used when the study includes ____ or ____ ____. (When counting the number of variables for the chi-square test, you do not distinguish between ____ and ____ ____.)

Answer 17

Single-Sample and the Multiple-Sample; “Single-Variable” and “Multiple-Variable” Chi-Square Tests; One Variable; Two or More Variables; Independent and Dependent Variables

Question 18

The ____-____ ____-____ ____ (also known as the goodness-of-fit test) is used when a descriptive study includes only one variable and the data to be analyzed are the frequency of observations in each category of that variable.

Answer 18

Single-Sample Chi-Square Test

Question 19

Example: The psychologist in Study #2 (treatment of Schizophrenia) is interested in finding out if the 120 patients in her study differ with regard to family background in terms of She determines how many patients have either (1) one biological parent who has received a diagnosis of Schizophrenia; (2) both biological parents who have received a diagnosis of Schizophrenia; or (3) both biological parents who have not received a diagnosis of Schizophrenia. Because this study is a descriptive study that includes only one nominal variable, the appropriate statistical test is the ____-____ ____-____ ____ and the degrees of freedom are equal to: (C — 1) = (3 — 1) = 2.

Answer 19

Single-Sample Chi-Square Test

Question 20

The ____-____ ____-____ ____ (also known as the chi-square test for contingency tables) is used when a descriptive or experimental study includes two or more variables and the data to be analyzed are the frequency of observations in each category.

Answer 20

Multiple-Sample Chi-Square Test

Question 21

Example: The psychologist in Study #2 wants to determine if a subtype of Schizophrenia is related to family background and determines each patient’s subtype and family history. The expanded study can be considered either a descriptive study with two variables or an experimental study with one independent and one dependent variable (family background is the IV and subtype is the DV). Because the study includes more than one variable and the analysis will involve comparing frequencies in each category, the appropriate test is the ____-____ ____-____ ____, and the degrees of freedom are: (C - I)(R - 1) = (3 - 1)(5 - 1) = 2(4) = 8.

Answer 21

Multiple-Sample Chi-Square Test

Question 22

Statistical tests for ordinal data include the ___________________________.

Answer 22

Mann-Whitney U Test, the Wilcoxon Matched-Pairs Test, and the Kruskal-Wallis Test

Question 23

Example: The psychologist in Study #2 assesses the effects of a phenothiazine on cognitive functioning by comparing the Full Scale IQ scores of patients who have received a moderate dose of the drug to the scores of patients who have received a placebo. The 10 scores turn out to be very skewed. Because the scores violate the assumption of normality for parametric tests, the psychologist converts the IQ scores to ranks and uses the ____-____ _ ____ to analyze the data.

Answer 23

Mann-Whitney U Test

Question 24

____ ____-____ ____-____ ____: The ____ ____ used when a study includes two correlated (matched) groups and the difference scores on the DV for pairs of subjects are converted to ranks.

Answer 24

Wilcoxon Matched-Pairs Signed-Ranks Test; Wilcoxon Test

Question 25

Example: The psychologist in Study #2 assigns patients to groups by matching them on the basis of their scores on a measure of premorbid adjustment and randomly assigning members of each matched pair to either the phenothiazine group or the placebo group. Because the study involves correlated groups and the IQ scores are not normally distributed, the psychologist calculates a difference score for each pair of matched patients converts the difference scores to ranks, and uses the ____ ____ to analyze the data.

Answer 25

Wilcoxon Test

Question 26

The ____-____ ____ is similar to the Mann-Whitney U test but can be used when a study includes two or more independent groups and the data to be analyzed are ranks.

Answer 26

Kruskal-Wallis Test

Question 27

Example: The psychologist in Study #2 expands her study by including four groups — one that will receive a high dose of the phenothiazine, one that will receive a moderate dose, one that will receive a low dose, and one that will be given a placebo. If the IQ scores violate one or both assumptions for a parametric test, the psychologist can convert the IQ scores to ranks and use the ____-____ ____ to analyze the data.

Answer 27

Kruskal-Wallis Test

Question 28

Study Tip: The main thing you want to remember about the tests for ordinal data is that they can be described as “____ ____” to specific parametric tests. The ___-____ is the nonparametric alternative to the t-test for independent samples; the ____ is the nonparametric alternative to the t-test for correlated samples; and the ____-____ is the nonparametric alternative to the one-way ANOVA.

Answer 28

Nonparametric Alternatives; Mann-Whitney; Wilcoxon; Kruskal-Wallis

Question 29

The chi-square test is used to analyze data collected on a nominal variable (or other variable that is being treated as a nominal variable). The (1) ____ sample chi-square test is used when a study includes only one (2) ____ and data on that variable are reported in terms of (3) ____. It would be the appropriate statistical test when a researcher asks a sample of 40 students to indicate which of five textbooks they prefer for an introductory clinical psychology class. The degrees of freedom for this study are equal to (4) ____.

Answer 29

(1) single-; (2) variable; (3) frequencies; (4) (5 - 1) = 4

Question 30

The (5) _____ sample chi-square test is used when a study includes (6) ____ or more variables and the data to be analyzed are frequencies in each nominal category. It would be the appropriate statistical test when a hospital director wants to compare the number of current adult male, adult female, adolescent male, and adolescent female in-patients who have received a primary diagnosis of either Major Depressive Disorder, Bipolar I Disorder, Bipolar Il Disorder, or Mood Disorder NOS. The degrees of freedom for this study are equal to (7) __________.

Answer 30

(5) multiple-; (6) two; (7) (4 - 1)(4 - 1) = 9

Question 31

The Mann-Whitney U test and the Wilcoxon matched-pairs test are used to analyze data when a study includes one (8) ____ variable with two levels and the data to be analyzed are reported in terms of (9) ____. The Mann-Whitney U test is appropriate when the two groups are (10) ______, while the Wilcoxon test is used when the groups are (11) ______.

Answer 31

(8) independent; (9) ranks; (10) independent (unrelated); (11) correlated (related)

Question 32

The ____ _-____ and the ____ of ____ are the most commonly used inferential statistical tests for variables measured on an ____ or ____ ____. There are several versions of both tests that are each appropriate for a different research design.

Answer 32

Student’s t-Test; Analysis of Variance; Interval or Ratio Scale

Question 33

The ____ _-____ is used to evaluate hypotheses about the differences between two means. There are three forms of the t-test — _-____ for a ____ ____, a _-____ for ____ ____, and _-____ for ____ ____ — and the selection of a t-test is determined by how the ____ ____ were ____.

Answer 33

Student’s t-Test; t-Test for a Single Sample, t-Test for Independent Samples, and t-Test for Correlated Samples; Two Means were Obtained

Question 34

Note that a t-test can be used to analyze data collected from a study involving ____ than ____ ____, but it would be necessary to conduct more than ____ _-____. This is problematic since, the larger the number of statistical comparisons made in any one study, the more likely that a ____ _ ____ will be made – i.e., the greater the number of “experiments,” the greater the ____ ____ ____. For this reason, the ____ of ____ is preferred when more than two means are to be compared (i.e., when the IV has more than two levels).

Answer 34

More than Two Means; One t-Test; Type I Error; Experimentwise Error Rate; Analysis of Variance

Question 35

____ _-____ for a ____ ____: The _-____ for a ____ ____.is used when a study includes only one group and the group (sample) mean will be compared to a known population mean. (In this situation, the population is acting as a ___-____ ____ ____.)

Answer 35

Student’s t-Test for a Single Sample; t-Test for a Single Sample No-Treatment Control Group

Question 36

____ _-____ ____ ____: The _-____ for ____ (____) ____ is the appropriate statistical test when a study includes two independent groups and the means of the two groups will be compared.

Answer 36

Student’s t-Test for Independent Samples; t-Test for Independent (Unrelated) Samples

Question 37

____ t-____ for ____ ____: The t-____ for ____ (____) ____ is used when the two means to be compared have come from correlated groups. It is the appropriate test, for example, for a study using a ____-____ ____ in which a ____ ____ of ____ will be ____ to ____ before and after the __ has been ____. It is also appropriate when subjects have been matched on an ____ ____ and members of each matched pair have been assigned to a ____ ____ or when subjects come to the study ____ ____ in ____ (e.g., twins).

Answer 37

Student’s t-Test for Correlated Samples; t-Test for Correlated (Related) Samples; Within Design; Single Group of Subjects; Compared to Itself; IV; Applied; Extraneous Variable; Different Group; Already Matched in Pairs

Question 38

Keep in mind that, when calculating the degrees of freedom for the t-test for correlated samples, ____ is subtracted from the ____ ____ of ____ of ____. In the above example, there are 20 pairs of pre- and posttest scores, and the degrees of freedom are 19 (20 — 1). If the study had involved matching 20 subjects on an extraneous variable and randomly assigning members of each matched pair to different groups, the number of matched pairs would be 10, and the degrees of freedom would be 9 (10 - 1).

Answer 38

One; Total Number of Pairs of Scores

Question 39

The t-test is used to compare ____ ____ ____ at the time and that the choice of a t-test depends on how the two means ____ ____. A study including more than two means (e.g., more than two levels of the IV) would require conducting ____ _-____, which would increase the ____ ____ ____.

Answer 39

Only Two Means; Were Obtained; Multiple t-Tests; Experimentwise Error Rate

Question 40

The various forms of the t-test are all used to compare two (1) ____. Although they can be used to analyze data from studies involving more than two means, this is problematic because it increases the (2) error rate which refers to the chance of making a Type (3) ____ error. The t-test for a single sample is appropriate for comparing an obtained (4) ____ to a known (5) ____. The degrees of freedom for a t-test for a single sample are equal to (6) ____, where N is the number of subjects in the sample.

Answer 40

(1) means; (2) experimentwise; (3) I; (4) group (sample) mean; (5) population mean; (6) (N - l)

Question 41

The t-test for (7) ____ samples is used to compare the means obtained by subjects in two unrelated groups. The degrees of freedom for this t-test are equal to (8) ____, where N is the total number of subjects in the study. Finally, the t-test for (9) ____ samples is used to compare two means when groups are related. Related groups are obtained in several ways. One way is by matching subjects for in their status on a(n) (10) ____ variable. Another way is pairs on the basis of subjects to act as their own (11) ____ (comparison) group. The degrees of freedom for this t-test equal (12) ____ where N is the number of (13) ____.

Answer 41

(7) independent; (8) (N - 2); (9) correlated; (10) extraneous; (11) control; (12) (N - 1); (13) pairs of scores

Question 42

If a psychologist conducts a study to compare the effects of two weight reduction programs, and he matches subjects in pairs in terms of their initial weight and assigns members of each pair to a different program, the t-test for (14) ____ is the appropriate statistical test. If the sample consists of 26 subjects, the degrees of freedom for this study are (15) ____.

Answer 42

(14) correlated samples; (15) (13 - 1) = 12

Question 43

The ____ of ____ (___) is used to compare two or more means. An advantage of the analysis of variance is that it ____ makes ____ ____ of ____ ____ while ____ the probability of ____ a ____ _ ____ at the ____ of ____ ____ by the ____. ln other words, an ANOVA helps control the ____ ____ ____.

Answer 43

Analysis of Variance (ANOVA); Simultaneously; All Comparisons of Group Means; Holding; Making a Type 1 Error; Level of Significance Set; Investigator; Experimentwise Error Rate

Question 44

There are several versions of the analysis of variance. Probably the most used are the ____-____ ___ and the ____ ___, which are appropriate when a study includes, respectively, ____ __ or ____ than ____ __. The other ANOVAs are used when a study employs a more ____ ____ ____.

Answer 44

One-Way ANOVA; Factorial ANOVA; One IV; More than One IV; Complex Research Design

Question 45

The ____-____ ___ is used when a study includes one IV and two or more independent groups and one DV that is measured on an interval or ratio scale. (When a study includes only ____ ____ ____ and involves comparing ____ ____ ____; the _-____ for ____ ____ and the ____-____ ___ are essentially ____, but the convention is to use the _-____ when the analysis involves comparing two means and the ___ when it involves comparing three or more means.)

Answer 45

One-Way ANOVA; Two Independent Groups; Only Two Means; t-Test for Independent Samples; One-Way ANOVA; Interchangeable; t-Test; ANOVA

Question 46

____ of the ____-____ ___: Like the t-test, the analysis of variance ____ ____, but it does so in a ____ ____ ____ by analyzing ____ ____ ____. More specifically, the ANOVA enables a researcher to evaluate the relative contributions of different factors to the ____ ____ of ____ observed in a ____ of ____. This is done by “____ the ____ of ____.” (Recall that the sum of squares is the ____ in the formula for the ____ and is a measure of the ____ of ____ around the ____ ____.) The one-way ANOVA divides the total sum of squares (SST) into a “____ ____ ____ of ____” (SSB) and a “____ ____ ____ of ____” (SSW) so that: SST = SSB + SSW

Answer 46

Logic of the One-Way ANOVA; Compares Means; More Complex Way; Variability Around Means; Total Amount of Variability; Set of Scores; Partitioning the Sum of Squares; Numerator; Variance; Variability of Scores; Distribution’s Mean; Between Group Sum of Squares; Within Sum of Squares

Question 47

The sums of squares are converted to ____ ____ (variances) by dividing each sum of squares by the appropriate ____ of ____ (for the ANOVA, the degrees of freedom are used not only to identify the ____ ____ but also to calculate the _-____): MST = SST/df; MSB = SSB/df; MSW = SSW/df

Answer 47

Mean Squares; Degrees of Freedom; Critical Value; F-Ratio

Question 48

MSW (mean square within) and MSB (mean square between) are then used to calculate the -____, which is also referred to as “” and is the test statistic produced by the ____ of ____. ___ is a pooled measure of variability within each of the treatment groups. It represents a ____ of ____ for subjects who have been ____ ____ and provides an ____ of ____ that is due to ____ ____. ___ is a measure of variability between treatment groups and serves as an estimate of variability that is due to ____ ____ and the ____ of the ____ ____. The F-ratio is calculated by dividing ___ by ___: F = MSB/MSW = (treatment + error)/error

Answer 48

F-Ratio; F; Analysis of Variance; MSW; Measure of Variability; Treated Alike; Estimate of Variability; Error Only; MSB; Both Error; Effects of the Independent Variable; MSB by MSW

Question 49

When the null hypothesis is ____ (when the IV has not had an effect on the DV), MSB and MSW are the same and F is equal to _. When the null hypothesis is ____ (when the IV has had an effect), MSB is ____ than MSW and F is ____ than _. The ____ the value of F, the more likely that it will be ____ ____.

Answer 49

True; Same; t; False; Larger; Greater than 1; Larger; Statistically Significant

Question 50

If a study includes more than two groups, a statistically significant F indicates that there is ____ ____ ____ the ____ but does not indicate ____ ____ ____. Consequently, when a one-way ANOVA yields a significant F, a ____-____ ____ is usually conducted to identify which ____ ____ are ____ ____.

Answer 50

Some Difference Between the Groups; Which Groups Differ; Post-Hoc Test; Group Means are Significantly Different

Question 51

A researcher might use the Scheffe S test to make all pairwise and complex comparisons (Group 1 vs. Group 2, Group I vs. Groups 2 and 3, Group 2 vs. Group 3, etc.) or the Tukey test to make pairwise comparisons when groups are of ____ ____. When a one-way ANOVA yields an insignificant F, ____ ____ ____ of the ____ is ____, and the null hypothesis is ____.

Answer 51

Equal Size; No Further Analysis; Data is Required; Retained

Question 52

The psychologist in Study #2 compares the effects of three levels of a phenothiazine on the WAIS-IV Full Scale IQ by obtaining a sample of 75 patients and randomly assigning them to either the high dose, moderate dose, or low dose group. After subjects have taken the drug for three months, she administers the WAIS-IV to all subjects and uses the ____-____ ___ to compare the mean Full Scale IQ scores of the three groups. Two different degrees of freedom are calculated for the ANOVA, one for the ____ and one for the ____. For this study, the numerator degrees of freedom are equal to: (C – 1) = (3 -1) = 2; the denominator degrees of freedom are equal to : (N – C) = (75 – 3) = 72.

Answer 52

One-Way ANOVA; Numerator; Denominator

Question 53

Note that the ____ ____ ia equal to the sum of squares divided by the degrees of freedom: ____ ____ ____ = 1352.64/2 = 676.32 and ____ ____ ____ = 8395.20/72 = 116.60. Also, the _-____ is equal to mean square between divided by mean square within = 676.32/116.60 = 5.80. The summary table indicates that this F-ratio is significant at the .05 level (p < .05), which means that the different doses of the phenothiazine have had significantly different effects on the Full Scale IQ score. To obtain more specific information about the relationship between phenothiazine dose and IQ score, a post-hoc test would be conducted.

Answer 53

Mean Square; Mean Square Between; Mean Square Within; F-Ratio

Question 54

____ ____ of ____: The ____ ___ is an extension of the one-way ANOVA and is used when a study includes two or more independent variables. (When a study has two IVs, the factorial ANOVA is also called a ____-____ ___, when it has three IVs, it’s called a ____-____ ___, etc.)

Answer 54

Factorial Analysis of Variance; Factorial ANOVA; Two-Way ANOVA; Three-Way ANOVA

Question 55

____ of the ____ ___: The logic underlying the factorial ANOVA is basically the same as that for the one-way ANOVA. The difference is that variability between groups is “____ ____ ____ so that F-ratios are obtained for the ____ ____ of each __ and their ____. For example, in a two-way ANOVA, an F-ratio is calculated for the ____ ____ of ____ _, the ____ ____ of ____ _, and the ____ ____ ____ _ and _ – i.e., F(A), F(B), and F(AxB).

Answer 55

Logic of the Factorial ANOVA; “Partitioned” Even Further; Main Effects; IV; Interaction(s); Main Effect of Variable A; Main Effect of Variable B; Interaction Between Variables A and B

Question 56

When any of the F-ratios are statistically significant, only the ____ ____ of the analysis has been ____. Because the study involves more than two groups, further ____-____ analyses are ____. However, when all of the F-ratios are ____, ____ ____ ____ are ____ and the null hypothesis is ____.

Answer 56

First Step; Completed; Post-Hoc Analyses; Necessary; INSIGNIFICANT; No Further Analyses are Required; Retained

Question 57

Use: Two or more IVs; Independent groups
One DV; Interval or ratio data
Statistic: F

Answer 57

Summary: Factorial Analysis of Variance

Question 58

Example: The psychologist in Study #2 wants to compare the effects of various combinations of three levels of the phenothiazine and four levels of therapy on cognitive ability. She obtains a sample of 120 patients and randomly assigns them to one of the 12 treatment groups. After three months, she administers the WAIS-IV to all patients. Because the study has two IVs (phenothiazine and therapy) and one DV that is measured on an interval scale, the psychologist uses a ____-____ (____) ___ to analyze the data she has collected. Results of the study will allow the psychologist to determine if there are main effects of phenothiazine dose, main effects of type of therapy, and/or an interaction between phenothiazine dose and type of therapy.

Answer 58

Two-Way (Factorial) ANOVA

Question 59

The one-way ANOVA is used when a study includes ____ ____ ____ while the factorial ANOVA is used when a study employs a ____ ____ - i.e., when it includes ____ or ____ ____ ____.

Answer 59

One Independent Variable; Factorial Designs; TWO or MORE independent Variables

Question 60

The two main forms of the analysis of variance are the one-way ANOVA and the factorial ANOVA. The (1) ___ ANOVA is used when a study includes one (2) ___ variable and two or more (3) ____ groups. It yields a single F-ratio, which is calculated by dividing MSB by MSW. MSB is a measure of variability that reflects (4) ____, and MSW is a measure of variability that reflects (5) ____ only.

Answer 60

(1) one-way; (2) independent; (3) independent; (4) treatment effects and error; (5) error

Question 61

MSB is (6) ____ than MSW, the F-ratio is greater than (7) ____, suggesting that the independent variable has had an effect on the dependent variable. The factorial ANOVA is the appropriate statistical test when a research study includes (8) ____ independent variables. It provides a separate F-ratio for the (9) ____ effects of each independent variable and for the (10) ____ between independent variables.

Answer 61

(6) larger; (7) 1.0; (8) two or more; (9) main; (10) interaction(s)

Question 62

If a psychologist conducts a study to compare the effects of four different weight loss programs for males and females, the study’s independent variable(s) are (11) _____. Assuming that the dependent variable is measured on a(n) (12) ____ or ratio scale, the appropriate statistical test would be the (13) ____ ANOVA.

Answer 62

(11) weight loss program and gender; (12) interval; (13) factorial (two-way)

Question 63

____ ____ of the ____ of ____: Several other versions of the ANOVA are available for use with more complex research designs.

Answer 63

Other Forms of the Analysis of Variance

Question 64

The ____ ____ ___ is a type of factorial ANOVA that is employed when “blocking” has been used to control an extraneous variable. It involves treating the extraneous variable as an ____ ____ so that its main and interaction effects can be ____ ____. It also increases ____ ____ by reducing within-group variability (i.e., each group is homogeneous regarding their status on the extraneous variable).

Answer 64

Randomized Block ANOVA; Independent Variable; Statistically Analyzed; Statistical Power

Question 65

The ____ ____ ___ would be the appropriate statistical test in Study #1 if the psychologist believed that initial symptom severity would moderate the effects of the self-control procedure on test scores and, consequently, assigned subjects to one of three groups based on their initial symptom severity (i.e., mild, moderate, or severe symptoms) and randomly assigned subjects in each block to either the self-control procedure group or the no procedure group. The randomized block ANOVA would provide _-___ for the main effects of ____, main effects of ____ ____ ____, and the ____ between procedure and initial symptom severity.

Answer 65

Randomized Block ANOVA; F-Ratios; Procedure; Initial Symptom Severity; Interaction

Question 66

____ of ____ (___): The ____ combines the analysis of variance with regression analysis and allows an investigator to control an extraneous variable by statistically removing the portion of variability in the dependent variable that is due to the extraneous variable. By removing the effects of an ____ ____, the ANCOVA reduces ____-____ ____, resulting in a more ____ ____. Conducting an ANCOVA requires using subjects’ scores on the ____ ____ (the “covariate”) to adjust their scores on the ____ ____.

Answer 66

Analysis of Covariance (ANCOVA); ANCOVA; Extraneous Variable; Within-Group Variability; Powerful Test; Extraneous Variable; Dependent Variable

Question 67

The psychologist in Study #1 could use the ___ to analyze his data if he did not consider subjects’ initial symptoms severity before assigning them to the experimental or control group but realized, after beginning his study, that a larger proportion of children with severe symptoms were assigned to the experimental group and a smaller proportion of children with mild symptoms were assigned to the control group. If children’s scores on a measure Of symptom severity administered prior to the beginning of the study were available, the psychologist could use the ANCOVA to statistically remove the portion of variability in academic achievement test scores that is due to differences in initial symptom severity. In other words, the ANCOVA would adjust the children’s academic achievement test scores to what they would have been if all children were the same in terms of initial symptom severity so that any difference between the experimental and control group children in academic achievement test scores would not be attributable to differences in initial symptom severity.

Answer 67

ANCOVA

Question 68

The ____ ____ ___ is appropriate for studies using a within-subjects design in which the different levels of the IV or combinations of the levels of two or more IVs are sequentially administered to each subject. The psychologist in Study # 1 would use the ____ ____ ___ to analyze the data he obtains in a study designed to determine if 6th grade children with ADHD who have been trained in self-instruction are better at solving math problems when completing a math worksheet in silence, while listening to nonvocal music, or while listening to vocal music and her study involved having the same group of 25 children complete a math worksheet in a different condition on three consecutive Friday mornings.

Answer 68

Repeated Measures ANOVA; Repeated Measures ANOVA

Question 69

As its name the ____ (____-____) ___ is the appropriate test for studies using a mixed design in which at least one IV is a between-groups variable and one IV is a within-subjects variable. It would be the appropriate test if the psychologist in Study #2 evaluated the effects of a phenothiazine on BPRS scores over time by randomly assigning 30 patients with Schizophrenia to either the low dose, moderate dose, or high dose group and administering the BPRS to all patients one week before taking the phenothiazine, four weeks after beginning the phenothiazine, eight weeks after beginning the phenothiazine, and 12 weeks after beginning the phenothiazine. In this study, phenothiazine dose is a between-groups independent variable and time is a within-subjects independent variable.

Answer 69

Mixed (Split-Plot) ANOVA

Question 70

____ ____ is used when the study involves one or more quantitative independent variables, and the researcher wants to evaluate the shape or form of the relationship between the independent and dependent variables. The results of a trend analysis indicate whether there is a ____ ____ ____ or ____ (quadratic, cubic, quartic) ____ ____ ____. The psychologist in Study #2 could use ____ ____ to determine if phenothiazine dose is related in a linear way to Pull Scale IQ score on the WAIS-IV (i.e., the higher the dose, the greater the benefits of the drug on the WAIS-IV score).

Answer 70

Trend Analysis; Statistically Significant Linear or Nonlinear Relationship Between Variables; Trend Analysis

Question 71

The ____ ____ of ____ (___) can be used when a study includes one or more independent variables and two or more dependent variables that are each measured on an interval or ratio scale. It allows an investigator to ____ assess the ____ of the ____ ____ on all of the ____ ____ and thereby helps ____ the ____ ____ ____. Also, when the IV has only a ____ ____ on each __, separate analyses might not ____ those ____; and the MANOVA helps ____ ____ ____ in this situation by ____ assessing the ____ of the __ on all of the __.

Answer 71

Multivariate Analysis of Variance (MANOVA); Simultaneously; Effects; Independent Variable(s); Dependent Variables; Control the Experimentwise Error Rate; Small Effect; DV; Detect those Effects; Increase Statistical Power; Simultaneously; Effects of the IV; DVs

Question 72

The psychologist in Study #1 could use the ___ to analyze the data she obtains when her study involves randomly assigning 30 6th grade children with ADHD to the experimental (self-control procedure) group or control (no procedure) group and, after children in the experimental group have received training in the procedure, administering three measures of academic achievement to children in both groups — i.e., a measure of math skills, a measure of reading comprehension, and a measure of written expression.

Answer 72

MANOVA

Question 73

When the results of a study indicate that a treatment’s effects are statistically significant, the researcher may also want to evaluate the ____ or ____ ____ of the ____. One way to do this is by calculating an ____ ____. ____ _ and ___ ____ are commonly used methods for calculating an effect size.

Answer 73

Practical or Clinical Significance of the Results; Effect Size; Cohen’s d and Eta Squared

Question 74

____ _ is a measure of the difference between two groups (often an experimental and control group) in terms of standard deviation units. It is calculated by ____ the ____ of ____ ____ from the ____ of the ____ ____ and ____ the ____ by a ____ ____ ____ for the ____ ____. For example, if a d of .5 is obtained in a comparison of treatment and control (no treatment) groups, this means that the treatment group obtained a mean that is ____-____ ____ ____ ____ the ____ of the ____ ____. Cohen provided the following criteria for evaluating the size of d: small effect size = _; medium effect size = _, and large effect size = _.

Answer 74

Cohen’s d; Subtracting the Mean of One Group; Mean of the Other Group and Dividing the Result; Pooled Standard Deviation; Two Groups; One-Half Standard Deviation Above the Mean of the Control Group; 0.2; 0.5; 0.8

Question 75

___ ____ (__) indicates the percent of variance in the outcome variable that is accounted for by variance in the treatment. For instance, if the psychologist in Study #2 obtains an eta squared of .55 for phenothiazine dose and scores on the BPRS, this means that 55% of variability in BPRS scores is accounted for by variability in drug dose.

Answer 75

Eta Squared (η2)

Question 76

Note that an effect size is also used in ____-____. It allows the results of different studies to be ____ to a ____ ____ so that results can be compared and an ____ ____ ____ ____ ____ ____ can be ____.

Answer 76

Meta-Analysis; Converted to a Common Metric; Compared; Average Effect Size Across Different Studies can be Determined

Question 77

Several forms of the ANOVA are available for more complex research designs. The (1) ____ ANOVA is used when a researcher wants to control an extraneous variable by statistically analyzing its effects on the dependent variable. Alternatively, the effects of an extraneous variable can be statistically removed by using the (2) ____.

Answer 77

(1) randomized block; (2) ANCOVA

Question 78

The repeated measures ANOVA is used to analyze interval or ratio data when a (3) ____ subjects research design has been employed. If a study includes at least one within-subjects IV and one between-groups IV, the (4) ____ ANOVA is appropriate. Trend analysis is used for identifying linear and nonlinear trends when the (5) ____ is quantitative.

Answer 78

(3) within-; (4) mixed (split-plot); (5) independent variable

Question 79

Finally, if a study includes one IV and four DVs, a researcher has a choice between conducting four (6) ____ ANOVAs or a single (7) ____. In this situation, the latter test is usually preferred because it helps reduce the (8) _________. Cohen’s d and eta squared are measures of (9) ____.

Answer 79

(7) MANOVA; (8) experimentwise error rate (probability of making a Type I error); (9) effect size