I should know more, but my experience is limited and old. As part of a field methods course including counting soil insects, we collected raw numbers in a whole lot of categories, then input them into a multivariate analysis program (SAS, at the time). We came up with a few interesting correlations, although none would probably hold up under better data collection methods. You could throw the data into a MVA program and see what comes out, then come up with a focus.
-Don Don Dean Oakland NJ Schools Project Amazonas Reforestation and Environmental Education projectamazonastree.org Join us in the Amazon in 2013! On Wed, Feb 6, 2013 at 4:15 PM, Christopher Brown <cabr...@tntech.edu>wrote: > Ecologgers, > > > > I have a master's student who is examining thermal preferences of two > species of scorpions in the Sky Islands of southeastern Arizona. She has > gathered some field temperature data as part of her thesis, but we are > unsure how best to analyze the data (or perhaps more specifically, what > data to analyze). I've given some details below, if you have some > insight for us! > > > > The short version of the experiment: these scorpions are found under > rocks during the day, and we have determined thermal profiles for 15 > rocks under which scorpions were found and 15 rocks under which > scorpions were not found. For both sets of rocks, we measured length and > width and selected a range of sizes based on binning the rocks into > three categories (small, intermediate, and large) and then choosing 5 > rocks in each size range. Each rock had an iButton placed under it, and > temperatures were recorded every 30 minutes for 48 hours. > > > > Her basic question is then, do the thermal characteristics of chosen > rocks differ from the thermal characteristics of non-chosen rocks? Our > problem is, what data should we use? Our first though is at a simple > level: we could calculate mean temps for the two rock categories and > compare them with a t-test, and/or we could compare variances or ranges > (max-min) with a t-test to determine if variability differs between > rocks. We've found a couple of different variations of this kind of > analysis in the literature, but we'd like to know if this is the best > (or "best") way to analyze the data, or are there more sophisticated > techniques that involve analysis of the whole profile? If we do use a > fairly simple analysis based on some type of summary variable, what is > the best summary variable to use (mean? Variance? Range? Something > else?) and the best analysis to do? > > > > If anyone has any experience in analyzing this type of data and has some > suggestions, we'd be happy to hear from you! > > > > Thanks, > > CAB > > *********************************** > > Chris Brown > > Associate Professor > > Dept. of Biology, Box 5063 > > Tennessee Tech University > > Cookeville, TN 38505 > > email: cabr...@tntech.edu > > website: iweb.tntech.edu/cabrown > > >
