The traditional morpheme order studies in second language acquisition have tried to
demonstrate the existence of a fixed order of acquisition of English morphemes, regardless
of the second language learner’s background. Such orders have been taken as
evidence of the preprogrammed nature of language acquisition. This article argues for a
process-based, dynamic explanation of development, in which each developmental step
is based on the dynamic interaction of all processes involved. Due to the complexity
of these interactions, the developmental process cannot be predetermined and fixed.
Although stages of development like the acquisition order of morphemes are commonly
observed as a grand sweep effect at the group level, these stages may be meaningless
at the level of the individual language learner. This paradox shows we can only make
the observations that our method allows us. If we are interested in grand sweep effects
that may be generalizable to large populations of learners, we will have to carry out
group studies with representative samples that can be analyzed using Gaussian statistics
based on the normal distribution. But if we are interested in how an individual learner
progresses over time as a result of changing variables in a changing context, we will
have to conduct longitudinal studies and use nonlinear methods of analysis.
Keywords variability; morpheme orders; dynamic systems; second language