Introduction

Traditionally we look at learning outcomes by examining single outcomes. A new and future direction is to look at the actual process of development. Imagine an advanced 17-year-old student of English (L2) who has just finished secondary school in the Netherlands and wants to become an English teacher. He first completes a teacher training programme, and later at age 30 he obtains a university master's degree in the Netherlands. After high school he is quite advanced already (estimated low B2 level), and when he finishes his MA thesis he is able to write an academic research paper with the proper academic register (estimated C2 level). The purpose of the present chapter is to gain insight into the linguistic developmental process of his academic writing from a dynamic perspective. Over the course of 13 years (with a gap of five years), he writes many texts, 49 of which are selected to be examined in detail. The analyses show that his writing development is a long, complex, dynamic process, in which different subcomponents of the language change in interaction with each other. During his teacher training programme the language develops substantially differently from his development during his university programme, where more of an academic register is expected. As the language develops, longer noun phrases occur, and more academic words appear, as reflected in a longer average word length. The linguistic system becomes more accurate as the process of acquisition continues, at one point quite abruptly, but even at the end of the participant's studies, the writing still contains some errors.

This study not only gives insight into the differences between the characteristics of advanced formal writing and academic writing, but also has implications for the assessment and measurement of linguistic development. It turns out that not a single dependent variable develops linearly, and they all may level off during development.