Resumen:
In CLIL research, Dalton-Puffer's recent construct of the Cognitive Discourse Function (CDF) (2013) - a taxonomy of seven cognitively and linguistically defined academic operations (such as explain or define) - is now gaining increased attention as a useful tool to make the question of integration of language and content more tangible and operational.
However, little is known about these functions¿ specific nature, their teachability, their possible impact on students' L2 content learning and their assessment. This paper aims to address these questions by focusing on one CDF in the CLIL science context, the CDF of comparing, a subtype of classifying.
The objective of this article is twofold. First, it provides a developed account of the CDF of comparing based on previous research, illustrated by qualitative insights from a study in which secondary students learned science through an explicitly CDF-based teaching approach, using representative pre- and post-test examples. Second, building on this enhanced understanding of the CDF, it presents an evaluation tool for assessing students' CDF-based content performance.
The discussion compares this analysis with previous research and outlines the advantages of an explicit CDF-teaching approach to help students significantly display their subject contents in a more complete, precise, and explicit way.
