# GU Research Mod 9

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1. Inferential statistics are based on the laws of ________.
probability
2. Inferential statistics provide a means for _________ about a population, given data from a sample.
drawing conclusions
3. The tendency for statistics to fluctuate from one sample to another.
sampling error
4. A theoretical (rather than actual) distribution b/c no one draws consecutive samples from a population and plots their means.
Sampling distribution
5. The SD of a sampling distribution of the mean.
Standard error of the mean (SEM)
6. The word ______ signifies that the various means in the sampling distribution have some error as estimates of the population mean.
error
7. The smaller the SEM, the _______ the means are as estimates of the population value.
• more accurate
• (less variable)
8. ___________ is used to estimate a parameter - for example, a mean, a proportion, or a mean difference b/w two groups.
Parameter estimation
9. With interval estimation, researchers construct a _________ around the estimate.
Confidence interval (CI)
10. What are confidence limits?
Upper and lower limits of confidence interval
11. A ________ distribution is the probability distribution of the number of "successes" in a sequence of independent yes/no trials, each of which yields "success" with a specified probability.
binomial
12. What is the best way to get representative samples?
probability samples
13. To estimate population parameters, it is advisable to use _______ samples.
representative
14. Researchers use inferential statistics to estimate _______ ________________ from _________ statistics.
• population parameters
• sample
15. Inferential statistics provide a framework for making _______ judgments about the _______ of sample estimates.
• objective
• reliability
16. The ________ of statistical calculations depends on the extent to which results from a sample are similar to what you would have obtained had you randomly selected people from the population.
validity
17. _________ involves calculating a single descriptive statistic to estimate the population parameter.
point estimation
18. _____ estimates convey NO info about margin of error so inferences about the accuracy of the parameter estimate cannot objectively be made.
point
19. ________ estimation is useful because it indicates a RANGE of values within which the parameter has a specified probability of lying.
interval
20. With _____ estimation, researchers construct a confidence interval (CI) around the estimate.
interval
21. Constructing a CI around a sample mean establishes a range of values for the population value as well as the probability of what?
being right! (the estimate is made with a certain degree of confidence)
22. THe CI is rarely ________ around a sample proportion.
symmetric
23. The ______ of the CI depends on the value of the proportion AND the sample size.
width
24. The larger the sample size, the _______ the CI.
smaller
25. The CI for a proportion never extends below ____ or above _____.
• 0
• 1.0
26. CI convey importan info about the _______ of the estimate.
precision
27. Hypothesis testing is based on _______ inference.
negative
28. Researchers make a ______ error by rejecting a null hypothesis that is actually true.
Type I
29. False negative conclusion.
Type II error
30. A ____ error might allow an ineffective drug to come onto the market.
Type I
31. A ________ error might prevent an effective drug from coming onto the market.
Type II
32. Researchers control the risk of a _______ error by selecting a level of significance.
Type I
33. A level of significance signifies the probability of ___________ a true null hypothesis.
incorrectly projecting
34. The two most frequently used significance levels are ___ and _____ and are referred to as ________
• .05, .01
• alpha
35. Increasing sample size will reduce the risk of a ______ error.
Type II
36. By selecting a significance level, researchers establish a ________.
decision rule
37. The decision rule is to reject the null hypothesis if the test statistic falls at or beyond the limits that establish a _________ on an applicable theoretical distribution and to accept the null hypothesis otherwise.
critical region
38. The ________ indicates whether the null hypothesis is IMPROBABLE given the results.
critical region
39. In one-tailed tests, the critical region of improbable values is in only one tail of the distribution - the tail corresponding to what?
the direction of the hypothesis
40. Easier or harder to reject null hypothesis with a one-tailed test?
easier
41. Two classes of statistical tests.
Parametric and nonparametric
42. _______ tests involve estimation of a parameter, require measurements on at least an interval scale, and involve several assumptions like variables are normally distributed.
Parametric
43. ________ tests do NOT estimate parameters and involve less restrictive assumptions about the shape of the distribution.
nonparametric
44. _______ tests are more powerful than ________ tests.
parametric; nonparametric
45. When comparisons involve different people (men vs women), the study uses a ______ design, and the statistical test is a test for _________.
• between-subjects
• independent groups
46. In ________ designs, comparisons are not independent b/c the same people are used in all conditions, and the statistical tests are tests for ________.
• within-subjects;
• dependent groups
47. ____________ refers to the number of observations free to vary about a parameter.
degrees of freedom
48. If the absolute value of the test statistic is ________ than the tabled value, the results are statistically significant.
larger
49. Any computed probability greater than ______ indicates non significance.
.05
50. A _______ can be used when there are two independent groups and when the sample is dependent.
t-test
51. When there are multiple dependent variables, the risk of a _______ error increases.
Type I
52. Researchers sometimes apply a __________ when they run multiple tests to establish a more conservative alpha level.
Bonferroni correction
53. The Bonferroni correction tends to increase the risk of ________ error.
Type II.
54. Incorrectly concluding there is no statistical association when in fact there is one.
Type II error
55. ______________ can be constructed around the difference b/w two means, and the results provide info about BOTH statistical sig and precision of estimated difference.
Confidence intervals
56. ________ is richer and more useful in clinical applications than p values.
CI
57. A _______ is computed from pretest and posttest data.
t-test
58. The ______ test involves assigning ranks to the two groups of scores.
Mann-Whitney U
59. The _________ test involves taking the difference b/w paired scores and ranking the absolute difference.
Wilcoxon signed-rank
60. ________ is the parametric procedure for testing differences b/w means when there are three or more groups.
Analysis of Variance (ANOVA)
61. The statistic computed in ANOVA.
F-ratio
62. ANOVA decomposes total _________ in a ______ variable.
• variability
• dependent
63. Variation between groups is contrasted with variation within groups to get _______.
an F-ratio
64. When differences b/w groups are large relative to variation within groups, the probability is _______ that the independent variable is related to or has caused group differences.
high
65. The ___________is the sum of sum of squared deviations of individual group means from the overal grand mean for all participants.
sum of squares between groups
66. The ______ is the sum of the squared diviations of each individual score from its OWN group mean.
sum of squares within groups
67. The function of __________ is to isolate the differences b/w group means that are responsible for rejecting the overall ANOVA null hypothesis.
multiple comparison procedures (post hoc tests)
68. In multiple comparison procedures, why is it NOT appropriate to use a series of t-tests?
b/c this would increse the risk of a Type I error
69. __________ is used to test the relationship b/w one categorical independent variable and a continuous dependent variable.
One-way ANOVA
70. __________ concerns whether the effect of one independent variable is consistent for all levels of a second independent variable.
Interaction
71. ________ ANOVA is used when thre are 3 or more measures of the SAME dependent variable for each participant.
Repeated-measures
72. Sum of squares-treatments is the same as the sum of squares-between in regular ANOVA and represents the effect of the ________ variable.
independent
73. The sum of squares-error is similar to the sum of squares-within in regular ANOVA and both represent variations associated with _______.
random fluctuations
74. The sum of squares-_____ has no counterpart in a simple ANOVA. Why?
• subjects
• b/c those being compared are not the same people
75. The SS-subjects term captures _______.
individual differences
76. _____ ANOVA yields a more sensitive test of the relationship b/w the IV and DV than ________ ANOVA.
• RM
• Between-subjects
77. What is removed from the denominator in computing the F-statistic?
variability attributable to individual differences
78. The ______ test is a generalized version of teh Mann-Whitney U test.
Kruskal-Wallis
79. The __________ test is based on assigning ranks to the scores of various groups.
Kruskal-Wallis or Mann-Whitney U
80. The ________ test is used when the number of groups is greater than two and a one-way test for indepenent samples is desired.
Kruskal-Wallis or Mann-Whitney U
81. The ________ test is for ANOVA by ranks .
Friedman
82. The _________ test is used to test hypotheses about group differences in proportions, as when a contingency table has been created.
chi-square
83. The _______ test enables us to decide whether a difference in propertions of a certain magnitude is likely to reflect a real tx effect or only chance fluctuations.
chi-square
84. _________ are the cell frequencies that would be found if there was no relationship b/w the two variables.
Expected frequencies
85. The _______ statistic is computed by summarizing differences b/w observed and expected frequencies for each cell.
chi-square
86. When is a chi-square test not appropriate?
• when sample size is small (30 or less), OR
• when there are cells with small frequencies (5 or fewer)
87. ___________ test should be used to test the significance of differences in proportions.
Fisher's exact
88. When the proportions being compared (pretest-posttest design is used to compare changes in proportions on a dichotomous variable) are from two paired groups the appropriate test is ________.
McNemar's
89. What is the correlation coefficient calculated when two variables are measured on at least the interval scale?
Pearson's r
90. Pearson's r summarizes the _______ and ________ of a relationship b/w two variables.
• magnitude
• direction
91. Pearson's r can be used both _____-group and ______-group situations.
• within
• between
92. If test scores are obtained before and after an event, the correlation b/w the two scores is a ______-group situation.
within
93. Pearson's r is a ________statistic.
parametric
94. When the assumptions for a parametric test are violated, or when the data are ordinal level, the appropriate coefficient of correlation is ____________.
• Spearman's rho OR
• Kendall's tau
95. The chi-square statistic is computed by comparing ______ frequencies with ______ frequencies.
• observed
• expected

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 Author: MeganM ID: 310899 Filename: GU Research Mod 9 Updated: 2015-11-11 00:43:51 Tags: Research polit beck Folders: GU,Research Description: Mod 9 Ch 17 p. 404-422 Show Answers:

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