and more cost-effective than formal, statistical, questionnaire-based surveys.
The reliability and accuracy of information obtained through such
surveys may be improved by (1) consciously avoiding common sources of
bias (e.g. visiting only farms that are easily accessible or favouring certain
types of farmers), (2) cross-checking of findings by using several different
methods and observing a wide selection of farms (e.g. 'triangulation') and
(3) stratification of the sample according to key variables (e.g. ecozones,
different groups of farmers).