For a one-way ANOVA, if k = 4 and n_1 = n_2 = n_3 = n_4 = 20, then a. df_between

Question

For a one-way ANOVA, if k = 4 and n_1 = n_2 = n_3 = n_4 = 20, then a. df_between = _____ b. df_within = _____ c. The number of levels for the factor is _____ A researcher wishes to test the effectiveness of 4 treatments (treatments A, B, C, and D) on depression compared to the control group (no treatment). Answer the following questions: a. How many planned comparisons would she perform? _____ b. Write the contrasts for each of the hypothesis below. (i) The four treatments are more effective than the no treatment; _____ (ii) Treatments A+B are more effective than Treatments C+D: _____ (iii) Treatment A if more effective than Treatment B: _____ (iv) Treatment C if more effective than Treatment D: _____

Explanation / Answer

Answer to part a)

The palnned comparisons would be between each treatment and the control group

thus there would be 4 planned comaprisons

.

Answer to part b)

i) Contrast: All treatments are same as No treatment in terms of effectiveness.

.

ii) Contrast: The effect of treatment A+B is same as C+D

.

iii) Contrast: The effect of treatment A is same as treatment B

.

iv) Contrast:The effect of treatment C is same as treatment D

.

Note: you must be wondering how "no effect' is in contrast to the term "effectiveness"

Let me explain: In such experiments our aim is to show that the treatments are better than the normal working (or as stated control situation) . So when the treatment is applied , and in case if it doesnot work , all the groups would be equally effective. this would imply that the treatment didnot work. This is the contrast to the statments provided in the question.

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.