ABSTRACT
The interconnections between research, policy and practice are considered in relation to five somewhat different types of research: descriptive studies that provide information about either language disorders or patterns of services for children with such problems; studies to test competing hypotheses about causal mechanisms; investigations of risk processes; evaluations of interventions; and basic research into some aspect of neural functioning. Studies of services provide findings in the clientele served and on patterns of service provision. Basic research involves similar considerations; it includes studies of normal language development, of neural processes, of psychopharmacology and of the different aspects of brain functioning. The three key issues with respect to the quality of descriptive research are those that apply to all studies: the adequacy of measurement, the representativeness of sampling, and the use of appropriate comparisons. The type of measures used will necessarily depend on the questions being examined and, for different purposes, psychometric methods, observational approaches and interviews.
