Question

An educator wants to evaluate four different methods aimed at reducing the time children spend "off task" in the classroom. To test these methods, she implements one method in each of four similar classrooms and records the time spent off task (in minutes) in each classroom. The results are given in the table.

Classroom Method
A	B	C	D
1	1	4	3
2	4	0	0
3	2	6	2
5	4	5	2
2	6	0	4
1	0	5	3
0	3	5	5
4	0	3	4
4	1	3	4

(a) Complete the F-table. (Round your answers to two decimal places.)

Source of Variation	SS	df	MS	F
Between groups
Within groups (error)
Total

(b) Is it necessary to compute a post hoc test? Explain. (Assume alpha equal to 0.05.)

Yes, post hoc analyses are appropriate because the ANOVA is significant.

No, post hoc analyses are not appropriate because the ANOVA is not significant.     

Answer 1

(a) Excel: Data --> Data analysis -->Anova: Single Factor

ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	7.19	3	2.40	0.68	0.57	2.90
Within Groups	112.44	32	3.51
Total	119.64	35

(b) Since P-value = 0.57 >0.05, we fail to reject H0.

Ans:  

No, post hoc analyses are not appropriate because the ANOVA is not significant.