Three robust scale estimators to judge unreplicated experiments

Results from unreplicated experiments can be evaluated by testing of standa rdized single degree of freedom contrasts with a robust estimator of their standard error constructed from the same contrasts. This paper presents con stants to calculate three estimators, and critical values to test the contr asts. The constants and the critical values depend on the number of contras ts. The paper covers all contrast numbers in the range from 7 to 127. It is proposed to make the choice between the estimators according to the resolu tion of the design.