This is the finished investigation using data collected by students in the project of their choice.

You forgot to add your files here.

oops :)

This post was edited by Anne Marie Levesque on Mar, 2009
Kristina

Too bad the student didn't have enough time to redo the experiment again using the mixture in ratio to what is used on the road in Falmouth. I am also wondering if the new mixture was more acceptable to plant life. It would be good if they can find an economical ecological friendly replacement to the road salt mixture.

Kristina,
I like the way that you gave the students a choice in their work. Too often we control what kids learn and don't give them the chance to find out things they really want to know.

Thanks. The student was really curious by the results. She had a great time doing it, and even won an award for it. She loved using excel too. It was so simple and straight forward.

Kristina,
Perhaps the 1st experiment is finding the optimum amount of water the plants like as reflected by their growth. Once this is known you could look at the relative toxicities of the two salts by varying the concentrations of each with each kid being responsible for two sets of plants. One set given rock salt the other CaCl but in equal concentrations and in the optimum (as determined by the previous experiment) amount.
Collectively your class could chart plant growth at say 0.1% 0.2 etc. solution for each of the salts.

It's great to see real world experiments to work on real world problems in which kids can make meaningful inferences.