The failure of development to improve the quality of life in most third world countries and in the less advantaged sectors of advanced capitalistic countries can be partially attributed, it is felt, to methodological errors made by those studying development. Some recent sociological approaches to the study of development are reviewed in this paper, and suggestions for clarification of the issues and approaches are made. Three major areas are discussed: (1) the definition of development; (2) the major approaches to the study of development--equilibrium models (behaviorists, psychodynamicists and diffusionists) and conflict models (structuralists--non-Marxist and Marxist); and (3) problems in analyzing relevant variables--confusion of structuralism with determinism, conceptualization, and the representativeness and validity of data. The economic situation of Colombia is described, and the five approaches are compared as to the treatment of 30 research questions relevant to the solution of Colombia's development problems. References are provided. (KM)