ENV330H5 Lecture Notes - Lecture 6: Analysis Of Variance, Statistical Unit, Unit
Document Summary
Data collected by technician y litter or nest mates statistically, the variation between blocks is removed from the experimental error term in an anova, increasing the precision of the experiment. Pro: controls for heterogeneity in a study system. Block what you can; randomize what you cannot. A randomized complete block design (rcbd) will be more efficient than a completely randomized design (crd) if there is more heterogeneity among blocks than within blocks. Every row has all the treatments; every column has all the treatments. Works well if you think you have a couple of gradients. Sometimes done when you are physically constrained (e. g. , your field isn"t big enough to do all your replication in one place, so you split your replicates among plots) Plot plots helpful when two (or more) treatment factors are being studied and the size of the experimental unit which is appropriate to the first factor is much larger than that required for the second factor.
