Study design

In the second stage of the sampling procedure, homesteads (Ultimate sampling units - USUs) were randomly sampled within selected dip-tank areas. 

In order to adequately cover each dip-tank area, it was decided to sample as far as possible 10 homesteads per dip-tank area (although some problems did arise) to give a total sample of 2,400 homesteads countrywide. 

This sample size (approximately a 1.3% sampling fraction) is comparable to that normally used by the Central Statistical Office in agricultural surveys for the country.