Empirical data demonstrate the value of t-way coverage, but in some testing situations, it is not practical to use covering arrays. However any set of tests covers at least some proportion of t-way combinations. This paper describes a variety of measures of combinatorial coverage that can be used in evaluating aspects of t-way coverage of a test suite. We also provide lower bounds on t-way coverage of several widely-used testing strategies, and describe a tool that analyzes test suites using the measures discussed in the paper.