My son is experiment-obsessed, and we own a number of experiment/science activity books. This one is easily the best so far. My son brought it home from his school's library, and we have had a lot of fun doing the experiments in it, some of them several times. It's been such a hit that I got it for my 6-year-old nephew as well. The experiments are easy to follow, involve materials that one either has or can easily acquire, and the results are fun and satisfying. It has been a great resource in the face of the "What-should-we-do"s. So we're finally returning it--and ordering our own copy. Furthermore, I'm going check out other Usborne activity books, since Christmas is coming up. Heartily recommended.