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Help on Analysis: Repeated measures? Split-Plot? Something else?I have a set of data that seemed straight forward, but now I am sure how to proceed. The experiment consisted of a single factor (fertilizer) with four treatments (fertilizer levels) and eight replicates (plants) of each treatment. Each replicate then had 5 data points collected on it (ie, 5 leaves from each plant were measured for area at a single time point).
I am not sure what the proper way to handle this data is. Do I consider this a repeated measures, since each replicate had multiple measurements? Can I consider the repeat observations as subplots and run a split-plot analysis? Or can I just average the data points for each replicate, and run an ANOVA?Re: Help on Analysis: Repeated measures? Split-Plot? Something else?You could use custom designer and set up a 2 factor categorical design. One at 4 levels (fertilizer amount) and the other at 8 levels 9 (plant type). I assume that you have used the same fertilizer and just different amounts of that fertilizer. After you generate the 32 treatment combinations you could then recode your fertilizer level by modifying the column properties as a continuous factor and code it accordingly and input the low and high levels. The responses for the plant measurements could be added as individual columns, Y1 through Y5 and a sixth column that represents the average of the 5 measurements could be calculated. In addition an additional column response of standard deviation could be generated. You could then model the average growth and standard deviation back to the continuous fertilizer amount and the 8 categorical plant types. Hope this helps.