From Dogs to Cats: Experimental Design Anna

Where you should be: Question Background Research Hypothesis Design and Experiment Results Conclusions

Question: Will a pecan tree die if I water it with salty water? Background Research: Salt, osmotic potential and pecan tree salt tolerance Hypothesis: Watering my pecan tree with a maximum of 35mg/L salt (seawater concentrations) will kill it because pecan salt tolerance is about 100 times lower. Experimental Design:

Variable-a parameter that changes What were the variables in my pecan-salt experiment? Salt Salt Concentrations What could be a control? (something I compare against my experimental variables?) A pecan tree with no salt added

Things to consider Materials Time Set up Where will the experiment be? Chemicals? Material Safety Data Sheet Balance? Plants? Buy them as seedlings or mature? Time how long will it last? When will you make your observations? Every day at what time? Set up Where will the experiment be?

Having developed an initial design, what could I improve on? Type of plant? Age of plant? Type of salt? Concentration of salt? Type of soil?

Replicates? You need to replicate (do several times) the same experiment to make sure its not a fluke! 3 is the minimum required in science RECORD EVERY SINGLE DETAIL Pictures Video Drawings Observations

What about you? What is your experimental design? Sum these things up in you project files: Hypothesis: I think X because of Y Experimental Variables Things you will be testing Controls Things you will be comparing the experiment against Design? And # Replicates

I’ll be here the rest of the period if you need help.