Exam II Flashcards
Which of the following refers to the group you wish to generalize your results to?
Population
Which of the following can be tested directly?
The research hypothesis
Which of the following is a directional test?
a one-tailed test
In order to help ensure generalizability, which of the following should be true about your sample?
It is large and representative
What test would you want to use to test a directional research hypothesis?
One-tailed test
Which of the following symbols represents the null hypothesis?
H0
When the sample accurately represents the population, the results of the study are said to have a high degree of…
generalizability
If you were to hypothesize that test scores from classroom A will be higher than test scores from classroom B, you have a:
Directional research hypothesis
What is the foundation of inferential statistics?
Probability
The fact that the trails of a normal distribution never touch the horizontal axis relates to the following property:
Asymptotic
If you want to calculate a z score for a test where your raw score was 24, what other information must you know?
Mean and standard deviation
What percent of all scores fall below a z score of +1?
84%
Z-scores which fall below the mean will be:
Negative
This percentage of scores fall within three standard deviations of the mean:
99.5%
If a distribution has a mean of 30 and a standard deviation of 5, how many standard deviations is 60 from the mean?
6
The level of chance or risk that you were willing to take is expressed as…
a significance level
When you accept a false null hypothesis, you are making a:
Type II error
Which of the following occurs when you accept the null hypothesis when it is really false?
Type II error
After you compare the obtained value with the critical value, you:
reject the null hypothesis if the obtained value is more extreme than the critical value
A smaller confidence interval would result in:
a smaller range of values in the confidence interval
If you want to examine the differences between the average scores of two unrelated groups, which of the following statistical techniques should you select?
Independent samples t-test
In order to determine whether or not you will reject the null hypothesis, the test statistic must be compared against the…
critical value
A(n)___ difference is due to some systematic influence and due to chance
significant
Which major assumption of the t-test deals with the amount of variability in each group?
variances are equal
The t-test for independent means is used when you are looking at the difference in average scores of one or more variables between____ groups that are_____of one another.
two, independent
In the formula that computes a t-value, what does X1-bar represent?
the mean of group 1
In the t-test for independent means, the actual statistical test is
Nondirectional
If the obtained value is greater than the critical value, what should you do?
reject the null
If one group had a mean of 2.3, and the second group had a mean of 2.4, and this was statistically significant, this result could be described as:
significant and not meaningful
If the number of participants in group 1= 54 and the number in group 2 = 58, what is the associated degrees of freedom (for a t-test)
110
A measure of how different two groups are from one another is the ____
effect size
What is the assumption that the amount of variability in each of the groups is equal?
homogeneity of variance
