Abstract The purpose of this paper is to examine the empirical research supporting the effectiveness, orineffectiveness of PBL as a teaching method. Secondly, if PBL is an effective method, what does researchsay about the relevance of PBL in connection to the Swedish secondary school curriculum. We took an indepth,critical look at the existing research to find any commonalities or any major contradictory findings.Results show that there is contradictory evidence regarding the effectiveness of PBL as a teachingmethod with the majority of support for PBL coming from the educational medicine field. Results also showthat very little research exists concerning how PBL relates to the guidelines set out in the Swedish Schoolcurriculum (GY11).After presenting the results we discuss the implications that PBL present as a teaching method, aswell as major problems encountered, and how these findings relate to the teaching profession in Sweden.Lastly, we discuss how further research could be beneficial to support the use of PBL.

The main focus of this thesis is on the effectiveness of project-based learning (PBL) in engineering design. The literature review has shown that there is much confusion and ongoing arguments concerning the implementation of PBL in engineering design, and there lacks consensus on its effectiveness. Little research has been done on providing measurable metrics of PBL effectiveness, not to mention discovering the optimal PBL and its underlying mechanisms based on solid educational theories and rigorous research methodology. In this thesis, the measurement of the optimal PBL effectiveness (effect) is studied and a theoretical model of PBL is built in order to identify parameters (cause) controlling the effectiveness and to study the interplay between effectiveness and the parameters. The model is built through three main phases, with a combination of qualitative and quantitative research methods. In phase one, the effectiveness of PBL is studied from the perspectives of the engineering design lecturers and engineering graduates by interviews, which is used to represent effect (Y axis) of the model. In phase two, on the basis of self-directed learning theory (SDL) and learner engagement theory,two key parameters of PBL, i.e. SDL and learner engagement, are identified and quantified respectively to represent cause (X axis) of the model. With the key parameters of PBL (X axis) and PBL effectiveness (Y axis) obtained, a theoretical model of PBL is proposed. The model is verified by means of experiments (student self-reported surveys). A specified Moving Average Method (MAM) is used for data analysis and findings demonstrate different trends of the relations between SDL and PBL effectiveness, and between learner engagement and PBL effectiveness. Consequently, a 3D model of PBL is built by combining the data in aforementioned 2D models,through which the optimal PBL effectiveness in 3D are identified and measured and the interplay between different parameters are found. In phase three, in order to find out more delicate features in PBL ignored by MAM, the dynamic interaction of individual differences in PBL teamwork is explored by the ethnological method (including participant observations and interviews), which is conducted as a supplement to the model of PBL. The theoretical model of PBL effectiveness proposed in this thesis is novel and groundbreaking. Firstly, a series of 2D and 3D models are presented and the relations between SDL, learner engagement and PBL effectiveness are revealed for the first time, which provides guidance for the optimal PBL measurement and implementation. Secondly, a qualitatively-quantitatively-combined strategy is used to discover the mechanisms controlling optimal PBL at different scales. Thirdly, the experiments verifying the model provide fresh quantitative insight into optimal PBL. In summary, the research in this thesis opens up a new research methodology for studying PBL effectiveness, which makes contribution to the educational field as well. Keywords: Project-based learning, Self-directed learning, Learner engagement, Optimal PBL effectiveness, 3D model, Individual differences, Engineering design, Pedagogy.