On Sat, Dec 08, 2001 at 03:35:11AM +0900, John Roth wrote: > Let's think about this for a moment. 5 test cases appears to > be adequate for a black box test. You need one for equilateral, > three for isosceles and one for scalene. If you're deriving > more test cases, you're doing an open box test, based on the > actual implementation (or on some set of assumptions about > frequent defects, or some such.) I think you need more tests than that, but more so because the requirements are wrong than anything else. A combination of three input values does not necessarily represent a valid triangle, so the function really cannot return "scalar" just because the three values do not represent an isosceles or equilateral triangle. So that's six more test cases (a+b=c, a+b<c, a+c=b, a+c<b, b+c=a, b+c<a). I don't think the requirements state that negative values should be disallowed (a negative value may simply represent a triangle that is upside-down). So we can't add more bad data tests without having better requirements. Paul