Findings, implications and lessons learned
Regression analysis
- There is a difference in mean
milk offtake between cows sampled in Bilisia and Assa.
- Milk offtake declined with age
of calf (or stage of lactation) at Bilisa but not Assa.
- Residual patterns in the data
suggest that certain observations may have been influential in determining the
fitted patterns and that there were others that possibly did not belong to the
overall pattern.
- The last point has implications
on the suitability of the study design that will be investigated further in the
study questions. It illustrates some of the difficulties in interpreting results
from small studies.
We have also seen how by switching of the order in which
the factor LOCATION is coded, in other words redefining the reference level, we
can calculate standard errors for both levels. |