Three Discussions on Object-Oriented Typing

This paper summarizes three discussions conducted at the ECOOP'91 W5 Workshop on ''Types, Inheritance, and Assignments'' Tuesday July 16, 1991 in Geneva, Switzerland, organized by the authors.   The three discussions were entitled ''Classes versus Types'', ''Static versus Dynamic Typing'', and ''Type Inference''. All these topics were assumed to be volatile and controversial; indeed, a broad range of diverging opinions were represented. However, much superficial disagreement seemed to be rooted in confusions about terminology. When such issues were resolved, there appeared a consensus about basic definitions and the - often incompatible - choices that one is at liberty to make. This clarification, which we hope to have described below, was the most important achievement of the workshop.