Hello and welcome to the 2009-2010 school year at Ann Arbor Open! The Open for Science blog is now officially revived!During these first two months of 7th and 8th Grade Science, we have been learning about photosynthesis and practicing the scientific method by conducting experiments on plant growth in the Ann Arbor Open School garden. Specifically, the students planted ryegrass, Lolium spp., a winter cover crop commonly sown by farmers in Michigan. They varied one factor between two rows to see if ryegrass growth, measured in centimeters, would be affected. The students
based their hypotheses upon their knowledge of photosynthesis, and they designed a range of interesting and solid experiments where plant growth was the dependent variable and factors such as light level, water amount, addition of fish emulsion, presence of vitamin C, paprika or calcium in the soil, or the addition of glucose or salt to the water were the independent variables. The students diligently followed their plants' progress and took their last measurements around October 14, and they have been writing up their reports ever since, working on data analysis and interpretation. 
This past week, the students have been learning about the null hypothesis * and its relevance to making decisions about interpreting results. The students have been happy to hear from me and several other adults, among them practicing biologists and social scientists, that learning what the null hypothesis is at the age of 12 or 13 will save them potentially weeks of trying to wrap their minds around this concept in college! Adolescent minds are so much more flexible in their learning, and the students' ability to incorporate the concept of the null hypothesis into their array of tools for the analysis of scientific observations is inspiring!
As we learned about plants and the scientific method, we were appropriately awestruck by the existence of photosynthetic slugs and predatory fungi. If you click on the highlighted links, you might be equally amazed by these creatures who surprise us by crossing the boundaries of our expectations for slugs and fungi!
* this link is to a very good and very funny description of the null hypothesis. Here's an excerpt: "Usually, the null hypothesis is boring and the alternative hypothesis is interesting. Finding that male chickens have bigger feet than female chickens might lead to all kinds of exciting discoveries about developmental biology, endocrine physiology, or sexual selection in chickens. Finding that male and female chickens have the same size feet wouldn't lead to anything except a boring paper in the world's most obscure chicken journal."
