Problem-based learning (PBL) is a student-centred pedagogic approach in which learners work collaboratively to solve problems and reflect on their experiences. It was pioneered and used extensively at McMaster University in Canada. It has also been widely applied in the UK within medical education.

PBL draws on social-cultural and constructivist theories of learning. Instead of presenting learners with information and asking them to understand and memorize it, PBL means the learners find out for themselves. Learners often find this approach more interesting and interactive and there is evidence that it leads to deeper learning, allowing learners to construct their own understanding.

Key characteristics of PBL include:

Introduction

Inquiry-based learning and related approaches such as project- and problem-based learning respond to the increased availability of information in a networked world by emphasising the location and application of information by the learner rather than its transmission from teacher to learner. The role of teacher necessarily shifts toward being a designer and facilitator of projects through which students learn rather than the primary source of knowledge in the classroom. That shift is facilitated by the application of digital technologies to initiate learning activities, access and process information, and present results. It confronts teachers with challenges in relation to the relative emphases on content and process in learning and assessment, and the role of learners in deciding what is learned and how.

CRITICAL QUESTIONS

Introduction

In the practice of engineering education, there is a wide variety of implementations of problem-based or project-based learning (PBL). In this chapter we aim to explain the relationships between different types of problem-based and project-based learning to help teachers and educational managers make innovative choices and provide benchmarks for educational researchers. We present a combined understanding of problem- and project-based learning, the theoretical and historical background, and the different models of PBL that can capture the existing practices, ranging from small- to large-scale practice, from classroom teaching to institutional models, and from single-subject to interdisciplinary and complex knowledge construction.

It is well known that one-way dissemination of knowledge by means of lectures is not very effective in achieving learning (van der Vleuten, 1997). In higher education concepts such as “self-directed-learning,” “case-based learning,” “inquiry based learning,” “experiential learning,” “service learning,” “project-based service learning,” “active learning,” CDIO (Conceive, Design, Implement, and Operate), “project-based learning,” and “problem-based learning” were introduced in the decades after the Second World War. All these new learning concepts come under the umbrella of learner-centered or student-centered learning models. Problem-based and project-based learning, both known as PBL, originate from the reform universities, and the new educational models, established between 1965 and 1975. In problem-based learning, problems form the starting point for students’ learning emphasizing a self-directed learning process in teams. The educational model problem-based learning was introduced at curriculum scale at the medical faculty of McMaster University, Canada, followed by Maastricht University in the Netherlands and many others. Project-based learning shares the aspect of students working on problems in teams, but with the added component that they have to submit a project report completed collaboratively by the project team. The problem- and project-based/project organized model adopted at Aalborg University and Roskilde University, Denmark, was inspired by the critical pedagogy in Europe after the student revolts of the 1960s. At Aalborg University both models of PBL were eventually combined in problem-based project organized learning, which was practiced at all faculties – the Faculty of Engineering and Science being the largest. This combined approach is the central point of reference for this chapter, as the pedagogical development in engineering education indicates that both educational practices are successful in their own way and the abbreviation PBL is here defined as including both practices.

This chapter provides a summary of some popular model-based deep learning methods and their extensions. Section 8.1 briefly describes classical model-based methods and their benefit as well as limitations. Section 8.2 describes how deep learning can help in overcoming some limitations of classical model-based methods. Section 8.3 discusses how to incorporate a pre-trained deep network as a regularizer using the plug-and-play approach. Section 8.4 describes end-to-end training using a model-based deep learning framework. This section also discusses some benefits and limitations of end-to-end training. Section 8.5 and 8.6 describe unsupervised model-based deep learning approaches when a clean training dataset is not available. Section 8.6 considers model mismatch issues as well as the joint design of acquisition and reconstruction frameworks.