The purpose of this paper is to compare and describe the development of the argumentative structure between Swedish students’ argumentative texts in compulsory school grade 9 and 2nd grade at upper secondary. For the analyses of the superstructure the following features have been investigated: claim, argument, support, counter-argument, refutation of counter-argument and conclusion. In addition, the feature digression has been included in this analysis, because, in the light of Krapels’ theory that skilled writers let their ideas influence and promote the text while weaker writers have difficulties in getting beyond mechanics i.e. elaborating the subject, the presence of digression might indicate that the writer actually is fairly skilled. Finally, I have included text length as a variable to be taken into account in this investigation. The argumentative texts investigated in this paper derive from the Nordwrite project which was conducted in 1986. In all, 36 texts are analysed in this investigation. 18 of them were written by students in compulsory school while the other 18 were written by students at upper secondary. Moreover, the texts are graded low, medium and high and each grade level contains an equal number of texts. The result of the investigation concerning text length shows that there is a significant difference between compulsory and upper secondary school, in that there seem to be a progression towards a standardisation of text length among writers at upper secondary compared to compulsory school writers’ texts which exhibit a greater variation in text length. Concerning digression I find that in compulsory school texts digression is more common among texts graded medium and high while none of the texts graded low include digression, whereas in the upper secondary texts the situation is quite the opposite. Finally, the superstructural features claim, argument, support etc. show a similar progression as in the case with digression. Nyckelord: Superstructure, claim, argument, support, counter-argument, refutation of counter-argument, conclusion, text length, digression, cultural interference, writing strategies.