  Over the last three decades, various didactic proposals have been published
in an attempt to connect theory and research findings with the design of
Teaching-Learning Sequences (TLS) in various contexts. Many studies have
analysed the process of designing teaching-learning sequences as a research
activity. This line of research aims to increase the impact and transferability
of educational practice.
  However, the information usually provided about the relation between the
theory and research findings with the design of the TLS is insufficiently
detailed to provide the basis for a critique. Furthermore, not all TLS
proposals include evaluation in terms of learning outcomes and very rarely are
these learning outcomes specifically related to the design process. This lack
of detailed information on the design and evaluation of proposed TLS makes it
difficult to properly assess their potential effectiveness or to systematically
discuss and improve their design. In this chapter we want to contribute to make
the rationale for design decisions explicit. The aim of this paper is to
describe in detail how the theoretical orientations of designers of teaching
materials towards cognition and learning can shape the structure and
pedagogical strategies of the resulting TLS. We will analyse the relationship
of two design tools (Epistemological analysis and Learning demands) to
theoretical assumptions about learning and the nature of science. We want to
highlight the benefits of reflecting on and discussing theoretical elements and
their links to design decisions, which makes TLS design more productive on a
practical level to broaden the teaching and learning perspectives of TLS.
Finally, we will explore the question to what extent the theoretical
orientations of curriculum designers towards cognition and learning can
influence the structure and pedagogical strategies of the resulting TLS
