Phonological Conditions on Affixation

Fortunately, most of the important generalizations that I draw based on the
present survey are positive generalizations. For example, as will be discussed, I have
found that PCSA can be conditioned by feet, syllables, moras, stress, tone, segments, or
features. This type of generalization is much easier to make than a negative
generalization, since any phenomenon for which there are multiple examples from
different language families (as is the case for the generalization stated above) is clearly an
‘attested’ phenomenon, regardless of the sample size.
In some cases, I do make negative generalizations. One such generalization is that
based on the survey data, it appears that there is no language in which PCSA in an affix is
triggered at the opposite edge of the stem; for example, there is no language where prefix
allomorphy is triggered by the stem-final segment. Of course, this generalization can be
falsified if another researcher uncovers such an example in future research. In that case, a
good scientific way to proceed would be to discern whether the apparent counterexample
can be interpreted so that it does not directly contradict the theory that was devised in
order to explain the generalization; if this proves impossible, then the theory should be
abandoned. In the mean time, my confidence that the generalization does reflect some
true fact about human languages (rather than a sampling error) can be increased by my
own deliberate efforts in constructing the survey, which I discuss below.
The best way to avoid making spurious negative generalizations is to make the
survey as large and broad as possible. I have attempted to do this in a variety of ways.
First, I have scoured several types of sources in my search for examples. About 600
sources were consulted in total, though of course not all of these yielded examples of
PCSA. Most of the examples to be presented were found by searching through
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