Combining diverse methods in a single study raises a problem: What should be done when the findings of one method of investigation conflict with those of another? The authors illustrate this problem using an example in which three study phases--quantitative, qualitative, and intervention--are applied. The findings from the quantitative phase did not fit those from the qualitative phase; there were discrepancies within the qualitative phase itself, and the findings from the single-case evaluations of the intervention using standardized scales did not fit the findings derived from self-made scales. The authors explain these inconsistencies by way of the complementary approach: Conflicting findings should be integrated, and consistency is restored by admitting complexity in the phenomenon under investigation. (Contains 1 table and 2 figures.)