chapter 12 study plan
Carolina conducts a study comparing the performance of individuals in three different statistics classes taking the same quiz. The scores, out of 100, are provided for individuals in each group. Class 1: 87, 78, 87, 85, 93, 98, 83, 82, 73 Class 2: 87, 86, 92, 90, 90, 91, 89, 78, 76 Class 3: 67, 78, 92, 85, 90, 98, 89, 82, 76 The value of F is:
0.229.
Rachael conducts a study comparing the performance of individuals in three different statistics classes taking the same quiz. The scores, out of 100, are provided for individuals in each group. Class 1: 77, 78, 87, 85, 93, 98, 83, 82, 73 Class 2: 87, 86, 92, 90, 90, 91, 89, 78, 76 Class 3: 87, 78, 92, 85, 90, 98, 89, 82, 76 The value of MSwithin, which is necessary to complete the final calculation of F, is:
47.843.
Researchers performed a study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 67 patients undergoing elective knee arthroscopy was randomly divided into three treatment groups. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery. The distribution to be used for the ANOVA test with this study is F(2, _____).
64
which statement is true
A post hoc test will let us know which specific pairs of means are different from one another.
Which statement regarding between-groups ANOVA is false?
A researcher is likely to reject the null hypothesis when F is close to 1.
Which statement regarding between-groups ANOVA is true?
A researcher is likely to reject the null hypothesis when the difference between means found in the data is much larger than the difference between means expected just by chance.
_____ is the proportion of variance in the dependent variable that is accounted for by the independent variable.
R^2
which statement is false? a. The Bonferroni test is more conservative than other post hoc tests. b. The Bonferroni test is sometimes called the Dunn multiple-comparison test. c. The Bonferroni test makes use of a number of comparisons for computation of alpha level. d. The Bonferroni test makes use of the Cohen's d test to compare the means.
The Bonferroni test makes use of the Cohen's d test to compare the means.
Researchers performed a study on the effects of a nonsteroidal anti-inflammatory drug (NSAID) given before and after arthroscopic knee surgery. A sample of 67 patients undergoing elective knee arthroscopy was randomly divided into three treatment groups. Researchers compared the mean pain scores of the patients in the three treatment groups one day after surgery, and the F value obtained was 4.79. Which statement is false?
The critical value for F for an alpha level 0.05 is 4.95.
When it comes to relationships between z, t, and F distributions, which statement is true?
The values of an F distribution are the squares of the corresponding values of a z distribution or a t distribution.
The _____ test is a widely used post hoc test following one-way between-groups ANOVA that determines the differences between means in terms of standard error.
Tukey HSD
A researcher conducts a study to compare the anxiety levels of three groups of individuals who are each taking a different antianxiety medication. The within-groups variance estimate of the population variance would be based on the:
average of the variances for each of the three drug groups.
Consider a study comparing the effects of three different drugs on memory for words in a recall memory test. The scores, which measure the number of words remembered, are provided for 18 individuals each tested after taking one of the drugs. Red Drug: 7, 9, 8, 9, 7, 8 White Drug: 5, 7, 6, 8, 9, 7 Blue Drug: 7, 7, 5, 5, 5, 6 The appropriate hypothesis test for this study is:
between-groups ANOVA, because there are more than two levels of the independent variable and there are different individuals in each sample.
Populations are described as _____ if the populations do not have approximately the same variance.
heteroscedastic
which statement is true a. If the research hypothesis is false, the observed variability in the sample means will be greater than the variability one would expect if the population means are equal. b. If the research hypothesis is true, the observed variability in the sample means will be less than the variability one would expect if the population means are equal. c. If the null hypothesis is true, the observed variability in the sample means will be greater than the variability one would expect if the population means are equal. d. If the null hypothesis is false, the observed variability in the sample means will be greater than the variability one would expect if the population means are equal.
d. If the null hypothesis is false, the observed variability in the sample means will be greater than the variability one would expect if the population means are equal.
When conducting a one-way between-groups ANOVA, the appropriate F distribution to serve as the comparison distribution depends on:
dfbetween and dfwithin.
To find the critical values for the Bonferroni test, the alpha level is _____ the number of comparisons between means.
divided
Samantha collects data from three different levels of an independent variable. She calculates the variance of the first group to be 117.6, the second group to be 118.3, and the third group to be 117.1. Based on these data, the populations are said to be:
homoscedastic.
Cohen's d is not used as the effect size measure for an ANOVA because:
it can be used only when there are two means.
The Bonferroni test might be a more appropriate post hoc test option than the Tukey HSD if the researcher wishes to be:
more conservative.
The Bonferroni test involves conducting a series of independent-samples t tests with:
more extreme critical values.
Which parameters of the study data do you start with when preparing to look up values in the F table?
number of samples, combined size of samples, and p level
The Tukey HSD test is also called a(n) _____ test.
q
A post hoc test is a statistical procedure frequently carried out after the null hypothesis has been _____ in an analysis of variance; it allows us to make multiple comparisons among several means.
rejected
If _____ sizes are unequal, a researcher using the Tukey HSD test must also calculate the harmonic mean.
sample
What is the defining difference between one-way ANOVA and two-way ANOVA?
the number of independent variables
The main purpose of ANOVA is:
to compare scores from three or more study groups.
A _____ ANOVA is a hypothesis test in which there are more than two samples and each sample is composed of the same participants.
within-groups
