"I learned there are more bugs after a rainstorm, less pH [potential of Hydrogen] in the water and more bacteria," Ian said.

Saratoga parent Karen Perizzolo organized this year's family science night at Foothill Elementary School in Saratoga, where children like Ian and Sam displayed the results of their experiments. At the annual event, more than 140 students from kindergarten through fifth grades demonstrated their experiments to passersby, including parents and teachers.

Perizzolo said she also volunteers teaching hands-on experiments to third-, fourth- and fifth-graders once a month as part of the school's science docent program.

"I hope it will become a self-sustaining program that will continue after I've left Foothill," said Perizzolo, who has a second- and a fifth-grader attending Foothill.

Perizzolo said the science curriculum at the elementary school level is often taught "cookbook style," where students are told what they should do and how to do it, instead of being allowed to think for themselves and solve problems on their own.

Principal Helen Sullivan said the science fair is not about competition or parent involvement; rather, every entrant receives a ribbon for participation. The projects are not graded, and students are encouraged to be creative. The children were given an overall format and scientific method to follow, Sullivan said, based on California education standards for science.

"It's an opportunity for them to work either as individuals or in teams," said Sullivan, adding that most students chose to work in groups.

She said the science fair was also a way for students to appreciate the projects of their fellow classmates as well as their own. The students had to research their projects, predicting answers to their experiments, measuring the results quantitatively and displaying the results on poster board with visual aids. The students had the freedom to develop any experiment they wanted.

"I encouraged them to actually come up with their own ideas instead of pulling them out of a general science project idea book," said Perizzolo, who has a background as a physician.

Topics ranged from the workings of the respiratory and digestive systems and water pressure to plant experiments and astronomy. Second-graders Julia Sakamoto and Katy Mattox named their experiment "Sugar and Spice and Everything Ice." The girls said they explored chemical reactions of ingredients such as sugar and salt with ice.

Second-grader Melis Akunal and her friend Isabella Zuccarino studied the decomposition of fruits, vegetables and meats in indoor and outdoor environments. Melis' father, Mehmet Akunal of Saratoga, said he hoped the experiment answered his daughter's natural curiosity about why and how food rots.

"It's good education for children to know how to take care of food," he said.