Teaching historical thinking and reasoning: Construction of an observation instrument S usanna Margr et Gestsd ottir* , Carla van Boxtel and Jannet van Drie University of Amsterdam, The Netherlands For some years, historical thinking and reasoning (HTR) have been important educational goals for upper secondary education in many countries. Nevertheless, teachers are often unsure of how to realise these ideas in the classroom. This article reports on the development of the domain-specific observation instrument Teach-HTR. It is intended for the further professional development of experienced history teachers who wish to foster historical thinking and reasoning, as well as to assist those who are doing their initial teacher training. The observation instrument was developed in sev- eral phases. A literature review was conducted to operationalise the dimensions of learning and teaching involved in historical thinking and reasoning. The content validity of this first version was evaluated by experts using a content validity rating form and subsequently revised. The final instru- ment consists of seven categories of teaching historical reasoning and 33 items. The instrument was piloted in 10 history lessons in Iceland and subsequently in 10 lessons in the Netherlands. Inter- rater reliability was evaluated using intraclass correlation coefficients (ICCs) and percentage of agreement. The internal consistency was evaluated using Cronbach’s alpha. In the second pilot, the instrument showed acceptable inter-rater reliability and internal consistency. The outcomes of the two pilots are described, and examples are given of lessons with high and low scores. The instru- ment can help identify concrete examples of teaching historical thinking and reasoning and points for development, which makes it a promising instrument for professional development. Keywords: historical thinking and reasoning; history teaching; observation instrument; professional development Introduction History teachers differ a great deal in their goals and teaching practices. Several researchers of history teaching have described at length the different approaches of dyads of (imaginary or real) teachers who at first sight seem direct opposites (Wineb- urg & Wilson, 2001; Barton & Levstik, 2004; VanSledright, 2011). Some of these teachers can be described as using a ‘doing history’ approach, which encourages his- torical thinking and reasoning (HTR). Active teaching approaches that foster histori- cal thinking and reasoning skills, such as the ability to understand that history is a construct in which many perspectives play a role, have been recommended in the lit- erature for some years. Nevertheless, many scholars also state that few history teach- ers adopt the ‘doing history’ approach, despite acknowledging its value and showing a *Corresponding author. University of Amsterdam, Research Institute of Child Development and Education, Roeterseilandcampus – gebouw B/C/D (ingang D), Nieuwe Achtergracht 127, 1018 WS Amsterdam, The Netherlands. E-mail: margret@fa.is. © 2018 British Educational Research Association British Educational Research Journal Vol. 44, No. 6, December 2018, pp. 960–981 DOI: 10.1002/berj.3471