The purpose of Research At Grass Roots is to accompany the novice researcher, in both the social sciences and human service professions, step by step through the research process. The description of the research process is probably unique in that this view has been developed over at least two decades through work with postgraduate students. The section for experienced researchers is less structured and discusses current topics of interest such as evaluation research, intervention research, participatory action research, and analysis of concepts such as evidence-based practice.

The interplay between scientific theory and research, and between research and professional practice, has once again been highlighted. This encompasses important debates for experienced researchers and practitioners, including crucial concepts for novice researchers to master as early as possible in their academic careers.

The section dealing with different models for combining quantitative and qualitative styles of research has been updated to include recent debates and developments in the field of mixed methods designs. Both sections dealing with qualitative and quantitative designs and analysis have been substantially revised and updated. We have included contributions from experienced researchers such as Prof. Willem Schurink, a qualitative researcher and doctoral supervisor, Prof. Wim Roestenburg, a senior academic and researcher, and Dr Allen Bartley, an international contributor and expert in statistical analysis. Prof. Minrie Greeff has again provided insight from her vast experience of research interviewing. Salient features of the previous three editions have been retained in order to ensure that we continue to meet the needs of current users of this very successful book.

The physical framework used to describe the various conversions is endoreversible thermodynamics, a subset of irreversible thermodynamics. "Thermodynamics of Solar Energy Conversion" provides an excellent generalized introduction into principles of solar energy conversion for everybody knowing some basics of university mathematics. Described are situations which are not in equilibrium and in which entropy is continuously created, but which are nevertheless stationary. In dealing with endoreversible thermodynamics, the given information in this book enables the reader to calculate the explicit values for a broad class of processes. It is demonstrated that solar energy conversion is a process particularly suited to being described in this way.

"De Vos is a wonderful storyteller"
--Prof. Dr. B. Andresen