Initially, upon reading this thread, I was all in favor of seeing testing done on various combinations. However, last night at work (very slow night), I was going through the archives, (esp. posts by G. Roberts), I found a variety of threads relating to the same subject. According to the posts, the same person doing the same work, can have 40% variation in the results from trial to trial. If this is the case, tests are highly misleading (either positively or negatively). As another post points out re: bridge building failures, most of the time, the information necessary to make "good" decisions is already available, it is just ignored (at our peril). In science, we tend to disregard data which don't support our conclusion, we don't even notice the data which might lead us off in another direction, or we don't understand the significance of the results (Sir R. Fleming thought he had discovered a first-class antiseptic when he found penicillin; he initially had no idea of its significance as an antibiotic.) In light of these complications, testing on a large scale probably doesn't give us much more to hang our decisions on than the current system of educated guesses. A final note, not too many areas receive more scrutiny in the form of trials/studies than pharmaceuticals (legal ones anyway). Millions of dollars and lots of experiments occur before a drug is approved by the FDA. However, it is not uncommon for problems to remain unobserved until the drug is in widespread release, being taken by thousands of people for a longer period of time. My point being (again) that trials/tests may only mislead us into thinking we "know" more than we actually do. Rick.