The state of the art in plate-load testing is briefly reviewed introducing some of the problems with the current modulus determination approaches. The METU dagger plate-load testing set-up introduced in this article is a new-generation testing facility which includes a hydraulically loaded stiff plate, and a multi-borehole displacement-measuring system. Emphasis is given to the description of the test set-up, the procedures required to carry out the tests and the interpretation of the test results. The step-by-step procedures for the derivation of the equations used to calculate the in situ deformation modulus (E-m) and Poisson's ratio (v) are given for both stiff-plate and flexible-plate loading. The least-squares method is used in the derivation. Using the METU method, instant, interval and overall moduli of the rock mass, as well as Poisson's ratio, can be identified. To illustrate this, typical results obtained from a test carried out in an underground test drift, are presented in the form of a stress-strain relation. (C) 1997 Elsevier Science Ltd.