Challenges to experimentation. These sources of complexity can make it
difficult to narrow down an experimental agenda and select developmentally relevant
lines of research. Proper selection of treatments and levels, appropriate
site conditions, and maintenance of experimental protocols are both
important and difficult to do. Because farmers are likely to establish and
manage systems in different ways, experiments to identify "optimal" technology
designs may be of far less practical value than experiments which
illustrate how system performance varies with changes in design (i.e., in
configurations, site conditions, or management).