If taught correctly this kit gets students to design an experiment without being spoon-fed the procedure. It almost certainly will require some guidance, but is worth it for the inquiry approach that is emphasized. Essentially students must figure out to create stock standards and use interpolation to determine the percent dilution of the "evidence" honey by using the principles of osmosis. In my advanced biology course it is the first "big" write-up of the year. There are plenty of places where students can make little mistakes that work as "teachable moments" and opportunities in the write-up for discussing how to improve their experimental design. Note that this is not a lab that can be done in one class period. I generally can get the kids through it in two, but sometimes the design process can take two periods itself. While I strongly recommend the kit, it is the sort of thing that, once you have the teaching materials you realize how easy it is to just go buy some honey and dialysis tubing to do it without the kit. But with that said, they do give you everything you need and it works well.
Pros:
easy to set up
inquiry approach
lots of opportunities to expand the discussion
Very effectively ties together the concepts of osmosis, water potential and quantitative testing.
Cons
You will need to do the dance of hinting at ideas without giving away key ideas of the design process
A lab based around honey can turn in to an awful, sticky mess.
Tying dialysis tubing can be a bit of a pain for the students.
You will almost certainly need multiple days for this lab. Many won't want to give it that much time.
Bottom line: Like so many experiments, the success of this lab is how you carry it out, but don't go in to this with the expectation that the kids will just pick up the materials and bang out the experiment because they know what osmosis is.
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