Abstract: | In many practical situations the experiment is conducted using a block design, and it is desired to estimate a given set of contrasts with variances none of which is greater than a corresponding set of specified variances: In the present paper the form of the intra-block matrix of a design is, therefore, derived for such situations. Usefulness of the results given is illustrated with the help of examples. The construction of two-plot block designs is shown to be particularly straightforward. |