The primary goal of this book is to show unity within the diversity of activities called social research. What the study of census data, the study of one person at a time, monitoring today's events, or reconstruction of social life centuries ago all have in common is that regardless of their case material, they construct representations of social life through a dialogue of ideas (theory) and evidence (data). To illustrate, Ragin points out the important continuities in three major forms of social research: qualitative study of commonalities; comparative research on diversity; and quantitative research on relationships among variables.