What is a summative test?
Summative testing is a comprehensive usability evaluation of a product or website in the context of how it is intended to be used in an actual use environment. Representative users take part in summative test sessions where they are asked to perform representative tasks under realistic conditions on final or near-final products or websites.
When should it be used?
Summative testing should be performed near the end of the product development phase on a final or near-final product or website. The goals of summative testing are to establish benchmarks for efficiency, effectiveness, and satisfaction; and to determine if the product or website has successfully met usability goals / success criteria that were established during formative testing.
What do you get?
The output from a summative test typically includes documentation of the findings for each task including performance summaries, a determination of whether or not usability goals / success criteria have been met for the product or website, a use error analysis discussing the results organized around a risk analysis of use, mitigation strategies for observed use errors, and recommendations for next generation releases or refreshes based on human factors principles.