This paper provides a discussion of structural test coverage metrics, looking at the practicality of their use for real software developments. It concludes that some metrics are unsuitable for real use, and recommends suitable combinations of structural coverage metrics for testing a range of integrity levels. It should be remembered that structural coverage based on control flow analysis is only a good starting point for thorough testing, and that other criteria for designing tests based on data flow and required functionality should be included in an effective testing strategy. It evaluates: statement coverage, decision coverage, LCSAJ coverage, path coverage, condition operand coverage, condition operator coverage and Boolean operand effectiveness coverage.