Hi Cindyluwho - I'm sorry to hear that your son has not been seeing crystals form as expected in the project. In addition to the other thread that John pointed out, this thread also contains advice and troubleshooting for this project:viewtopic.php?f=24&t=7297&p=29137
In addition, the advice from Donna, part of our team of Experts at Ask an Expert, may prove helpful if it turns out that your son doesn't observe crystals after another trial.
Here are a few additional suggestions and things to check that may help:
-- starting with the syrup at room temperature may help with crystal formation
--the humidity of the environment can affect crystal formation. How was the weather during testing?
-- make sure the pan is VERY clean. Water, oil or soap residue can cause a problem with the formation of crystals
Let us know how it is going and if you have additional questions.
Good luck with the project!