Textual resources for the construal of classificatory knowledge: Taxonomies in natural science textbooks

Abstract

This paper focusses on the linguistic construal of scientific knowledge in teaching-learning contexts. It aims to map the organisational structure of classificatory texts included in science textbooks and to identify the lexical resources associated with the verbalisation of classification systems. The study draws upon systemic functional linguistics (Halliday, 2014) and the Sydney School’s genre studies (Martin & Rose, 2008). The main methodological steps comprised the creation of a corpus of 100 classificatory texts, extracted from natural sciences textbooks (2nd and 3rd cycles of elementary education) used in Portugal, and the identification of their stages, based on the schematic structure of the taxonomic report genre. The results show a significant lack of obligatory stages, as well as the extended use of an optional stage: Orientation. The classification system stage was further analysed, focusing on its semantic and lexicogrammatical patterns. An irregular presence of different semantic elements was identified, as well as the use of lexicogrammatical resources that do not construe classification knowledge per se. It is argued that instructing students on the classificatory genre’s contextual and textual properties is essential to enhance their ability to comprehend and produce texts.