Capstone Chapters 6 - 10
the second type of t test examines
(dependent (paired)) pre- , post- situation people in the group are the same (ex. warm up protocol)
the first type of t test examines
(independent t test) two different groups of people exercise vs control
A researcher finds a correlation of .70 between popularity ratings and self-concept scores. What percentage of common association can be inferred between the two variables?
49%
Which hypothesis is stated in the null form?
There is no difference between the vocabulary scores of average- and high-ability students
A null hypothesis is
a statistical hypothesis that assumes that there is no difference among the effects of treatments
Prediction studies use which of the following as the basic analysis technique?
correlation
what does x stand for?
independent variable
To determine whether data are normally distributed, one can test to see whether the curve is shifted to the left or right. This shift is called
skewness
The t test is used to
test whether two groups differ significantly
When an experimenter states that the level of significance is the .05 level, he is setting the probability of committing which type of error?
type I error
For a predicted score of 30 and a standard error of estimate of 6, the chances are 95 out of 100 that the true score will be between
18 and 42
A researcher wishes to know whether there is a significant difference in the number of knee injuries reported among four sports. How many degrees of freedom are there for this chi-square analysis?
3
The researcher obtained a significant F from the ANOVA. Omega squared was found to be .30. This is interpreted to mean that
30% of the total variance is accounted for by the treatments
What is the mode(s) for the following set of numbers? 5, 10, 4, 1, 4, 5, 12, 8, 9, 4
4
What is the median score for the following set of numbers? 3, 11, 8, 13, 5, 3, 6
6
A statistical technique that tests for significant differences between observed and expected frequencies of occurrence is
Mann-Whitney test
What does r stand for? (name of statistic)
Pearson product moment correlation coefficient
Which of the following statements does not describe an advantage of repeated measures?
Repeated measures can eliminate the influences of some unwanted variable
what does a Bonferroni technique adjust for?
adjusts multiple comparisons shrink the alpha to prevent a type I error = falsely rejecting a null hypothesis
A researcher sought to find out which of two exercises was more effective in building endurance. One group used exercise A, and another group used exercise B. At the end of the study, the researcher should compare the two groups' scores by
an independent t test
To determine which of two methods for learning a motor skill is more effective, the correct statistical analysis is
an independent t test
When the purpose of the research is to determine the effects of one independent variable (e.g., four groups) on one dependent variable (e.g., self-concept), the best choice of a statistical analysis is
analysis of variance
A main disadvantage of nonparametric techniques that has frequently been stated (although there is some disagreement with this claim) is that they
are not as powerful as parametric techniques
what does between represent?
between the groups comparing group means
The single score which best represents all the scores in a distribution is the definition of
central tendency
Scheffe
conserevative
A chi-square analysis compares the responses to a question on recreational preferences of males and females at three grade levels. The resulting two-way classification structure is called a
contingency table
A researcher wishes to determine whether a treatment group made a significant improvement from the pretest (M = 25) to the posttest (M = 30). The correct statistical test to use to compare the two means is the
dependent t test
what does Y stand for?
dependent variable
A measure of meaningfulness that expresses the difference between the experimental and control group in standard deviation units is the
effect size
A researcher decides to use an alpha of .01 and a power of .80. To determine the needed sample size the researcher must ascertain the expected
effect size
the third type of t test examines
examining a sample vs a population (ex. freshman vs entire university)
A correlational technique frequently used in the construction of an instrument (such as an attitude inventory) that statistically groups test items that seem to be measuring a particular dimension or trait is called
factor analysis
A correlation of .00 between two variables indicates
independence (no association) between the variables
The term that describes the position of the hump in the curve of a distribution is
kurtosis
Duncan
liberal
If two measures have a high positive correlation and a person has a low score on one measure, his or her score on the other measure is most likely to be
low
Tukey
middle
If there is a correlation of .80 between a test of scholastic aptitude and performance on an achievement test, one can infer that
no causation can be inferred
Data such as sex, city of residence, or political party affiliation are what kind of measure?
nominal
In multiple regression, one is able to predict
one criterion from two or more predictors
what does b stand for?
slope
The standard deviation represents the
spread of scores about the mean
Which of the following terms least belong with the others? mode mean standard deviation median
standard deviation
If a researcher finds a small difference in average test scores between a large sample (over 700) of experimental participants and a large sample (same size) of control participants, it is very likely that the difference is
statistically significant but does not have a high degree of meaningfulness
After a population of 1,000 high school seniors is divided by sex and size of school attended, the random selection of a sample to represent these proportions of the population is called
stratified random sampling
When a researcher decides that an appropriate analysis for a research model is to evaluate how several variables might influence two other variables that in turn influence the outcome variable of interest, the appropriate statistical analysis is
structural equation modeling
A researcher wishes to survey student opinions on a proposed increase in fees at her university. She decides to select a sample for telephone interviewing by selecting every 20th name in the student directory. What is this type of sampling called?
systematic
Four skills tests are tried as predictors of success in a tennis class. Each test correlates with later success as follows: test A, r = .27; test B, r = -.90; test C, r = -.40; test D, r = .65. The test that will most accurately predict success is
test B
When a researcher states that a result is significant, this means that
the result is unlikely to be a chance occurrence
A two-way (factorial) ANOVA with more that one person per cell will yield F values for which of following contrasts?
three F values, one each for rows, columns, and interaction
When a researcher claims that there is a difference between treatments (i.e., rejects the null hypothesis) when there really is no difference, what type of error is this?
type I error
If the researcher fails to reject the null hypothesis when there really is a difference, this is an example of a
type II error
Use of a one-tailed versus a two-tailed test of significance of the difference between two sample means depends on
whether the difference is expected to be in one direction only
If ANOVA has found a significant difference among four treatment groups, a follow-up test such as the Scheffe is needed to determine
which of the groups differ significantly from the others
what does within represent?
within the groups comparing individuals within a group
what does a stand for?
y - intercept
formula for a regression problem
y = a + bx + bx2 + bx3 + ... bxn