Today Kara started class off by showing us some more ways to do statistics. We went over ANOVA variants, including two way ANOVA, nested ANOVA, and ANCOVA. Since our collection of covariate data is growing, these will likely be useful tools in our next statistical tests. Transformations were also introduced, along with GLMs (generalized linear models).
Next, we took another look at the concept web we made earlier in winter quarter. Data was classified as “Main effects” and “Covariates” to help us organize our thoughts. For instance, our treatment types (0, 10, & 40% gall x high or no gall trees) and resource quality (colonization & pinning) are the main effects we are testing in the experiment. These are directly related to the big picture question we are asking: How do the treatments affect the number and diversity of emerging insects? So far, the idea is that higher galls will reduce fungal growth, which then has bottom-up effects on insects. However, there could be effects from the covariates (such as distance of tree from the river, or moisture level in our pots), which will also be tested. We’ll see what the data says!
Lastly, we finished the class with some lab work. This included finishing data collection of soil sample dry weights, looking at insects in vials to confirm morphospecies data was entered correctly, and cleaning the growth chamber.
Here is a list of the assignments that will be due in the coming weeks:
Wednesday, May 13, 2015
- Revisit your hypotheses from the Outline assignment we completed before.
- Find out what data we have and statistics that could be used to test these hypotheses.
Wednesday, May 20, 2015
- Complete a draft of methods and results to prepare for the final paper.
- Choose a hypothesis (or a few) that you are specifically interested in. Each person’s paper can be different.