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Re: Scientific method
If you want to compare two treatments you must supply replicates for EACH
treatment. The question you then ask is whether the two means are different
from eachother (this of course implies that you are measuring some
parameter of importance). The two sets of data are then compared
statistically
to determine if the values within one treatment are significantly
different from the values within the second treatment. You do this using
what is called a t-test. You can also use what are called
'non-parametric' statistics if you want to simplify your design.
You cannot test two treatments if there are no replicates because you
have no 'degrees of freedom' which is another way (kind of) of saying
that you dont know the variability within a treatment and therefor you
dont know if it is 'different' than any other treatment.
dave.