Introduction

Inquiry-based teaching is one major trend in science education. Although it has been expanding and appearing in several educational guidelines across the world, it conceptualization remains a challenge for science education researchers and educators. Primarily, inquiry-based teaching is might be considered a complex activity which encompasses a great variety of different actions.

Inquiry-based teaching and teachers' practice

The inquiry-based teaching is a popular approach in science education that aims to overcome the traditional instructional methods used in science lessons which usually are focused on conceptual learning and teacher-centered activities. Although inquiry-based teaching has been related to student-centered activities with the focus on scientific practices and reasoning it is hard to outline any core commonalities, as such approach varies depending on teachers' plan, the amount of time and guidance, the particular perception of scientific inquiry,  and so on. This approach might comprise a wide range of goals, tasks, methods, and assessments.
As noted by Furtak (2012) the notion of inquiry has different meanings in science education literature. This concept has been used to conceptualize scientific practices, instructional design, a way for students to learn science and curriculum materials. On the one hand, such a conceptual fuzziness yield a rich variety of studies and teaching experiences which enable teachers to try out assembling diverse processes and different degrees of guidance. Furthermore, it allows researchers and teachers to acknowledge a whole set of aspects usually overlooked in science classrooms (e.g., nature of science, emotion, argumentation, dialogue, decision making and agency). On the other hand, it brings difficulties to settle practices over time and cross context. Therefore, there is an intrinsic challenge in developing comparative studies and measuring effectiveness. Rönnebeck (2016) argues that literature provides little accounts on a holistic perspective of scientific inquiry as they underline:
Conceptual saturation in terms of a predominant model can only be identified for single activities, while research on other activities can mainly be characterised by diversity. Hence, further theoretical work as well as empirical research regarding the interplay of different inquiry activities as well as their individual contribution to the inquiry process as a whole is needed.