That's what we used to call re-creating lab notes, working from the results you should have gotten and concocting experimental results to match. Now there's a whole new kind of dry-labbing: virtual science labs (HT Joanne Jacobs). The comments on Joanne's blog are mixed: on the one hand, this looks like a terrible idea--reminiscent of virtual finger-painting software (no mess!) and the whole phenomenon of "experiencing" life in textbooks inside a classroom that drives so many parents to homeschool; on the other hand, with growing class sizes and increased concerns about school safety (and liability), it can be a safe way to do dangerous experiments, especially experiments that were performed by the instructor anyway, with the students watching. Further, it seems that students using the virtual lab instead of the hands-on lab have higher pass scores on the Chemistry AP Exam. You don't learn how to fix an experiment that isn't working, and you don't get unexpected results that can teach you something else (these have been prominent features of homeschool chemistry); but you don't risk blowing things* up, either.
Virtual chemistry is of obvious interest to homeschoolers. In the standard litany of Concerns About Homeschooling, the corollary to "Parents obviously can't teach all the advanced high school subjects at home" is "You can't duplicate a chemistry lab at home." Putting aside the questionableness of the assertion, should the appearance of virtual chemistry, and the encouraging reports about its success rate, be good news for homeschoolers? Or is it bad news for public school kids, who may be losing one more reason for being in school?
The chemistry text we use, General Chemistry by Whitten, comes with CDs featuring virtual experiments which have helped Offspring #1 to grasp some concepts more fully than a mere prose description or an attempt to reduplicate the experiment at home. Many of the experiments, even with the fairly good home lab we're setting up, would just be impossible for us to do, due to hazard level or expense. A mix of hands-on and virtual labs seem the obvious--and for us, necessary--way to go.
*Great quote from link: "And people ask me why I don't like chemistry."