Statistics – 1

Published on 23/05/2015 by admin

Last modified 23/05/2015

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57 Statistics – 1

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1. ANOVA is used to compare two groups.
2. Scales with multiple answers increase reliability in measuring attitude.
3. The chi-squared test of a 5 by 3 contingency table will have 15 degrees of freedom.
4. The chi-squared test could be used in a study of response to a new antidepressant in four different hospital populations.
5. Correlation is used to compare two groups.
6. Regarding correlation coefficient ‘r’, a value of +1 or −1, implies a cause–effect relationship.
7. Knowing the outcome status in a cohort study may lead to information bias.
8. A type II error occurs when a real difference is missed.
9. Observer-rated scales are prone to ‘halo effect’.
10. The least squares method is used for dichotomous variables.
11. Logistic regression is done by the least squares method.
12. Means taken from large samples of a skewed distribution approximate to a normal distribution.
13. T² test is used for non-parametric variables.
14. Normal distribution is a requirement for parametric testing.
15. The power of a test varies with the size of the sample.
16. Volunteer bias would deter healthy people from responding to postal questionnaires.
17. R² usually increases if a further independent variable is added.
18. Operational definition of concepts used in rating scales increases reliability.
19. Newspaper advertising can be used for random sampling.
20. Psychiatric screening instruments used in a general hospital are usually used to detect uncommon syndromes.
21. In a trial of two antidepressants, failure to show a difference in outcome may be due to there being less than 5% of subjects with previous episodes of depression.
22. A result statistically significant at a level of 5% implies that the correlation coefficient is 0.95.
23. A sensitive test has a low number of false positives.
24. Split-half reliability measures the validity of a test.
25. In an experiment to determine whether drug therapy or hypnosis is better as a treatment to stop smoking, the results are measured by the number of cigarettes smoked after treatment. In this study, hypnosis is a dependent variable.