Answers are grounded in this paper and cite their sources.
Huynh Huynh, Leonard S. Feldt, Estimation of the Box Correction for Degrees of Freedom from Sample Data in Randomized Block and Split-Plot Designs, Journal of Educational Statistics, Vol. 1, No. 1 (Spring, 1976), pp. 69-82
No takes yet. Share an insight, caveat, or question.
Huynh et al. (1976) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: