I am beginning to think that being able to freely run experiments anywhere is begining to become part of the problem. This is particularly so for Kerbin EVA, where so many science points are available around the space centre. this combines with another problem that orbital EVA sciance is biome specific,requiring you to get Kerbals in and out of the capsule all of the time. I would replace the current science system with a system of 'academic' contracts, which would require specific experiments to be run in specific locations, and would be the primary source of science. These contracts could then be tuned, so that simpler contracts become less available as time goes on, to reflect the 'biome exhaustion' effect seen with the current science system. However, it is unlikely that with any system like this, a player would get as much science from Kerbin as currently available. One necessity of this, though is to make there a sufficient number of different contracts that a player is given options of a wide variety of different missions. On the other hand, it is quite easy to have more different contract types than there are experiements. While part tests can be included in this, I would ideally want part tests to be a slightly different approach. A part test would allow free use of a part without it's technology being researched. However, to reduce the possibility of abuse of test parts, the part would not be functional for other uses until tested (a tested engine, for instance would not activate when staged until in the correct location for testing). The ultimate developement of this, which mught be a bit excessive, would be to have 'technology demonstration' as an alternative to part entry costs, where to unlock any part (or group of similar parts, to avoid the system being too boring) when it becomes availble, you would have to do an associated contract. These contracts would sometimes be tests of that part, but not always. You could sometimes have special 'test' versions of similar parts (described as being modified to simulate the new part). You could have special materials bay tests (for example, one test for an LV-N would be to test the shielding material in low Jool orbit). One restriction on making this sort of system fun is to make the test mission make some sense. for example there is no value in testing a vacuum optimised engine on the launch pad, and there is no point in testing parts outside the Kerbin-Mun-Minmus system, unless tesing in an atmosphere or a high radiation environment.