This is a close up of one of my book shelves. The entire shelf is full of Facts on File science experiment binders. I have Junior Environmental Activities on File, Earth Science Experiments on File, Science Experiments on File, More Science Experiments on File, Junior Science on File, Junior Science Experiments on File, Janice VanCleave's Science Experiment Sourcebook, Nature Projects on File, and Charts on File on that shelf. I have been regularly checking out Science Experiments on File from my local library. While there are still the usual experiments that teach very little, it has some very good demonstrations (I especially like the ones for stalagmites and classification). If there are still a good portion of the experiments that I wouldn't use, why is this such a score? Because I got all of the binders in a box for $6. Yep--$6!
As an example, the Junior Science Experiments on File has experiments for kindergarteners through 6th grade. Safety guidelines, basic skills, physical sciences, life sciences, earth science, and teachers' hints are grouped separately. i've included a couple of examples. The life science example with the celery is a great lower elementary (K through 3) activity especially when the different colored water is used. The pulley demonstrates appropriately a simple machine and gives a point of comparison by moving to a set up using two pulleys. A great experiment for upper elementary (3 to 6).
I would not claim that these books are great. There are just as many (if not more) experiments that I would not bother with as there are those that I like, but the ones I like I like a lot. They are generally more useful than those found on-line. I like the included data table examples and the directions are clear. The experiments do not demand massive expenditures. The equipment is what one would expect to use for any general science.