The mechanism approach calls attention to an intermediary level of analysis, in between pure description and story-telling, on the one hand, and grand theorizing and universal social laws, on the other. These essays, written by prominent social scientists, advance criticisms of current trends in social theory and suggest alternative approaches. For social theory to be of use for the working social scientist, it must attain a high level of precision and provide a toolbox from which middle range theories can be constructed.
This book should be the Bible of all social scientists. Well, perhaps not all, but a good portion of them. "The Scandanavian book" will help you to understand the goals of mechanism related research and the analytical leverage one gains from adopting such an approach.