1 What are the basic assumptions of a oneway ANOVA Which one

1. What are the basic assumptions of a one-way ANOVA? Which one of these is most often neglected by researchers? How does accounting for assumptions make a study stronger?

2. What is the null hypothesis for a one-way ANOVA?

3. What are the 3 null hypotheses in a Factorial ANOVA?

4. Inflated Type I errors are often corrected by adjusting the level of significance (as with Bonferroni). What is another technique to reduce Type I error risk and how does this technique differ from Bonferroni?

5. What is a familywise error rate and when is it used?

6. What are the 3 types of variables in any ANCOVA study?

7. What is the purpose of the covariate in an ANCOVA? This answer should include how it can improve over ANOVA.

8. When using ANCOVA why do many researchers seem to feel that this procedure was designed to permit nonrandomly formed groups

Solution

1) All samples are drawn from normally distributed populations

2) All populatins have common variance.

3) All samples are drawn independently i.e. one does not depend on the other

4) Strict randomness observed in each sample

5) Factor effects are addictive.

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2) Null hypothesis: All means of different groups are equal

3) H0: An interaction is there

Ha: No association or interaction between various groups

4) Another method is to increase the sample size.

This differs from bonferroni in that as sample size increases confidence interval gets narrower giving more accuracy

5) Familywise error rate is the probability of making one or more false inferences or type I errors, among all the hypothesis.

This is used in multiple hypothesis tests.

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6) Dependent, independent , covariate

7) Covariate gives an estimation about the expected value of two variables combined.

Suppose for a x, we have one y

list all (x,y) together and find an association or covariance between them help to predict one from the other.

8) This is because this is more a minute process of checking such that randomness not being present also can be overcome by this pattern of 3 variables test.