S. Kluge. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research On-line Journal http://www.qualitative-research.net/fqs/fqs-d/rubriken-d.htm, 1 (1):
20 Absätze(January 2000)
M. Feuer, L. Towne, and R. Shavelson. Educational Researcher, 31 (8):
4(2002)“For example, when well-specified causal hypotheses can be formulated and randomization to treatment and control conditions is ethical and feasible, a randomized experiment is the best method for estimating effects” p. 8.