[Evaluation of public health services].

The Nordic Congress on Public Health, at Gothenborg, in June 1995, was focused on questions of evaluation. The article reviews basic evaluation concepts, presents a checklist for the planning of evaluation, and proposes an evaluation strategy, as well as standardised terminology for use in trials related to the spread of innovations. The following terms are proposed: news trials, demonstration trials, acceptance trials, and quality assurance trials, each type of trial being linked with appropriate methods. It is suggested that Nordic consensus on this terminology should be achieved as a basis for common language and understanding.