This paper reports on a project aimed to explore how the proportion of newly introduced word-types and lemmas varies in different adaptations of the same text. The term ‘adaptation’ is used here to include both intralingual and interlingual adaptation, whether involving reduction in text size or not, as well as what we usually class as (interlingual) translation. The first part of the study looks at the way lemmatization affects the appearance of new words in a text. It was found that there are only minor differences between the appearance of word-types and lemmas, which means that lemmatization is not absolutely necessary in an analysis of the introduction of new words. In the next part of the study another type of adaptation, i.e. translations into foreign languages are analyzed. It was found that changes on the discourse level are independent of the language. This is equivalent to saying that if there are differences between the translations they must be due to inadequate translation. The third type of adaptation examined was two condensed versions of the original text. In this case the question was the extent of vocabulary changes affected. It was found that the condensed versions eliminated exactly those text-slices of the original text which made it unique. As a result, there are only minor differences between the condensed versions and a statistical model that assumes a hypergeometrical distribution of words. The method used made it possible to determine the source of the second order adaptation.