Introduction

In their daily practice, teachers face diverse groups of students for whom they are expected to provide optimal learning opportunities (Tomlinson et al., 2003). It is expected of teachers that they implement ‘within-classroom differentiation’, i.e. that they adapt their instructional behaviour on the learning needs of their students. Differentiation is thought of as a complex skill (Van der Grift, 2014) that requires teachers to know their students and which task or learning activity is appropriate for their students (Deunk, Doolaard, Smale-Jacobse, & Bosker, 2015).  Many studies focus merely on teacher differential behaviours and its effects on student outcomes. However, to support teachers in their development of differentiation skills, there is a need for studies that map why teachers do what they do. Studies that shed light on the knowledge and cognitions that are relevant when teachers adapt their teaching so professional development programs can address these.

Differentiation and adaptivity

Within the current research literature there seems to be a variety of conceptualizations of differentiation. In some studies differentiation is researched as a rational and seemingly straightforward decision process. This process typically starts with a valid and reliable assessment of relevant student characteristics to which teachers proactively adapt their education (Brimijoin, Marquisse, & Tomlinson, 2003; Rock, Gregg, Ellis, & Gable, 2008). For example, teachers can assess students’ preferred learning styles or their interests in particular topics, and plan their lessons accordingly. In many studies using this conceptualisation it is stated that teachers hardly differentiate in their lessons (Subban, 2006; Tomlinson et al., 2003).

This rational perspective on adaptive teaching has been critiqued and expanded with the views that this approach might not do justice to the complex nature of education where multiple goals are strived for within the same situation (Bulterman-Bos, 2004; Corno, 2008), and that the relevant student characteristics to be adaptive to as well as the best ways to do so are affected by a teacher’s beliefs. Although the adaptive teaching process can be highly rational, teachers might choose different educational adaptations to respond to perceived differences, influenced by their normative beliefs. What appropriate teaching is, and which learning needs are seen as relevant to be addressed by teachers, then, are not only empirical questions but also ideological ones (Barrow, 2015; Corno, 2008). Research from this perspective shows that teachers use their personalized perceptions of students to decide on their instructional decisions (Paterson, 2007). To shed light on teacher differentiation it thus is necessary to include their personal constructions of student needs and how they respond to these.

Although the adaptation towards students’ ability seems to prevail in research on differentiation (cf.  Deunk et al., 2015), students in classrooms differ across numerous other domains, such as motivation, interests, preferences, social skills, cultural backgrounds, and many more (Waite, Boyask, & Lawson, 2010). Not all these domains are guiding teachers’ adaptive behaviours; which characteristics when and how matter is influenced by what is perceived as salient within a particular context (Plaut, Cheryan, & Stevens, 2015). To shed light on teachers’ adaptivity and differentiation, it is important to understand how teachers perceive their students and how such perceptions receive their salience. In our study we investigate which perceived student characteristics are relevant for teachers’ adaptive practices and which considerations teachers use when adapting their teaching to student differences.

Barrow, R. (2015). Curriculum theory and values. In Entwistle, N. (ed), Handbook of educational ideas and Practices, (pp. 110-117), New York: Routledge Bulterman-Bos, J. (2004). Teaching diverse learners: A practice-based perspective. Dissertation VU: Amsterdam. Brimijoin, K., Marquisse, E., & Tomlinson, C.A. (2003). Using data to differentiate instruction. Educational Leadership, 60, 70-73. Corno, L. (2008). On teaching adaptively. Educational Psychologist, 43, 161-173. Deunk, M., Doolaard, S., Smale-Jacobse A., & Bosker, R.J. (2015). Differentiation within and across classrooms: A systematic review of studies into the cognitive effects of differentiation practices. Groningen: Gion, Rijksuniversiteit. Maulana, R., Helms-Lorenz, M., & Van de Grift, W. (2015). Development and evaluation of a questionnaire measuring pre-service teachers’ teaching behaviour: a Rasch modelling approach. School Effectiveness and School Improvement, 26, 169-194. DOI: 10.1080/09243453.2014.939198 Plaut, V.C., Cheryan, S., & Stevens, F.G. (2015). New frontiers in diversity research: conceptions of diversity and their theoretical and practical implications. In Mikulincer, M., & Shaver, P.R., APA Handbook of Personality and Social Psychology: Vol. 1. Attitudes and social cognition. (pp. 593-619). http://dx.doi.org/10.1037/14341-019 Rock, M.L., Gregg, M., Ellis, E., & Gable, R.A. (2008). Reach: A framework for differentiating classroom instruction. Preventing School Failure, 52, 31-47. Subban, P. (2006). Differentiated instruction: A research basis. International Education Journal, 7, 935-947. Tomlinson, C.A., Brighton, C., Hertberg, H., Callahan, C.M., Moon, T.R., Brimijoin, K., Conover, L.A., & Reynolds, T. (2003). Differentiating instruction in response to student readiness, interest, and learning profile in academically diverse classrooms: a review of literature. Journal for the Education of the Gifted, 27, 119–145. Van der Grift, W.J.C.M. (2014). Measuring teaching quality in several European countries. School Effectiveness and School Improvement, 25, 295-311. Waite, S., Boyask, R., & Lawson, H. (2010). Aligning person-centred methods and young people’s conceptualizations of diversity. International Journal of Research & Method in Education, 33, 69-83.