Abstract
The research purpose of this PhD thesis is to promote Algorithmic Thinking (AT) at school, with 9 to 15 years old learners, in an active engaging way, which asks learners neither to passively listen to a teacher, nor to sit in front of computer screens. The work in this thesis is based on a socio-constructive approach to learning, in which learning takes place by interacting and working together with peers or teachers. Moreover, in this approach, learning is stimulated by activating different learning modalities besides the visual or auditory ones; manipulating tangible objects, in particular, fosters the interaction between abstraction and concreteness, so that learners with tangibles may solve problems which they would find difficult to solve by means of an abstract representation only. This is the case of Graph AT (briefly, GAT), which requires the ability to understand an abstract representation like a graph, model a problem with it, design and explore strategies (algorithms) to solve the problem by relying on graph properties. Therefore this thesis pursues the scaffolding of GAT through ad-hoc interactive tangible objects (briefly, tangibles). The research reported in this thesis evolves around the design of tangibles and actions with them for the scaffolding of GAT, a topic rarely dealt within schools, and yet relevant and applicable in different educational contexts. Tangibles come with companion scenarios, which serve to guide the design of tangibles and their usage in class. Tangibles for GAT at school are essentially a new topic, therefore this PhD research is exploratory and descriptive in nature: it seeks to envision or describe products and their usage in relation to their context of use. It adopts a design approach which is based on Action Research and it follows a series of cycles around a novel situation, which is poorly understood. Initially, cycles adopt an exploratory stance, in which an initial understanding of the situation is formed. Exploratory design solutions are then developed and adopted by their intended users in GAT actions. Results are described and reflected over, in order to uncover novel research spaces and possibly trigger new Action Research cycles, in which tangibles and the understanding of their context of use are developed and acted upon. This PhD thesis is organized as follows. Firstly, it introduces the context and sets the ground for the thesis research: it reviews related work in the area of AT, and it concludes with a list of challenging open issues. Starting from them, it derives the main research questions of this thesis. The thesis proceeds and describes the research methodology it adopts, that is, Action Research, focusing on the roles of teachers and learners in the design of tangibles and scenarios. The central part of the thesis presents the tangibles and their companion scenarios. The thesis continues and presents the core studies, firstly exploratory studies and then a field study with learners from different schools. Data are collected and reflected over with different methods and from diverse perspectives. This dissertation concludes by answering the research questions and identifying directions for on-going and future work concerning the design of GAT actions with tangibles and methodological reflections.