Questions to be addressed

The questions that we shall address in the Data management section are:

• How to reduce the raw data to provide mean values for the different time units?

• What criteria should be used to decide whether data from individual animals should be included or not?

• How to include the effects of other factors such as age and sex in the process?

• What terms to include the final statistical model to test the null hypothesis of no effect of tsetse control on livestock productivity variables?

An impact of an intervention may not necessarily be immediate and make take a few months to be seen. This has indeed been found to be the case with tsetse control (Leak et al., 1995). In the final analysis we shall make decisions on how to relate periods of control with the timing of impact outcomes.