Written in response to George Fairweather's position concerning the use of experimental studies in evaluation, this paper highlights considerations in deciding when experimental procedures are feasible. The current debate on the use of experimental methods in evaluation is reviewed. (Author/GK)

Studies examining the effectiveness of early intervention for infants and children with organic impairment and and developmental delay were reviewed using recently developed quantitative methods. Results suggest an accurate interpretation of the early intervention research literature cannot be made without consideration of specific design…