Test coverage is enhanced by measuring various types of coupling between coverage tasks. The coupling measurements may be implicit coupling measurements, explicit coupling measurements, coding coupling measurements, performance coupling measurements, resource coupling measurements or the like. Coupling scores are calculated for coverage tasks and based thereon ranking of the coverage tasks or groups of coverage tasks may be determined The ranking may be utilized in selecting for which uncovered coverage task a test should be designed. The ranking may be utilized in computing a coverage measurement of a test suite. The ranking may be utilized to rank tests, based on the coverage tasks each test covers. Ranking of tests may be utilized for various purposes such as performing test selection.