Question

Use an appropriate design to evaluate the effect of forest type on chick survival, while accounting for variation in elevation.

1) State all relevant hypotheses (nulls and alternatives).

2) State which test was used and why you used it.

3) State conclusions after completing your analyses.

Forest type	Elevation	chick survival
edge	1	0.21
non-edge	1	0.34
edge	2	0.45
non-edge	2	0.38
edge	3	0.35
non-edge	3	0.57
edge	4	0.14
non-edge	4	0.58
edge	5	0.21
non-edge	5	0.28
edge	6	0.61
non-edge	6	0.69
edge	7	0.53
non-edge	7	0.47
edge	8	0.13
non-edge	8	0.36
edge	9	0.24
non-edge	9	0.32
edge	10	0.41
non-edge	10	0.68

Answer 1

From above plot we observe that data come from normal distribution hence two way ANOVA test with one observation per cell is most appropriate here. This design is called randomised block design (RBD). Here we consider Elevation is as a blocking factor and Forest types are treatments.

3.

Two-way ANOVA: chick survival versus Forest type, Elevation

Source         DF        SS         MS       F      P
Forest type   1   0.085805 0.0858050 7.63 0.022
Elevation       9 0.333205 0.0370228 3.29 0.045
Error             9   0.101245 0.0112494
Total            19   0.520255

Since both p-values<0.05 so we reject both null hypotheses and conclude that here blocking factor (i.e. Elevation type) and Forest types (i.e. treatments) have significant effect on chick survival.