1960s under the banner of bringing 'scientific thinking' to geography led to an increased use of technique-based practices, including an array of mathematical techniques and computerized statistics that improved precision, and theory-based practices to conceptualize location and space in geographical research. Some of the techniques that epitomize the quantitative revolution include: Descriptive statistics; Inferential statistics; Basic mathematical equations and models, such as gravity model of social physics, or the Coulomb equation; Stochastic models using concepts of probability, such as spatial diffusion processes; Deterministic models, e.g. Von Thünen's and Weber's location models. The common factor, linking the above techniques, was a preference for numbers over words and a belief that numerical work had a superior scientific pedigree. Ron Johnston and colleagues at the University of Bristol have published a history of the revolution that stresses changes in substantive focus and philosophical underpinnings as well as methods. Epistemological underpinnings The new method of inquiry led to the development of generalizations about spatial aspects in a wide range of natural and cultural settings. Generalizations may take the form of tested hypotheses, models, or theories, and the research is judged on its scientific validity, turning geography into a nomothetic science. One of the most significant works to provide a legitimate theoretical and philosophical foundation for the reorientation of geography into a spatial science was David Harvey's book, Explanation in Geography, published in 1969. In this work, Harvey laid out two possible methodologies to explain geographical phenomena: an inductive route where generalizations are made from observation; and a deductive one where, through empirical observation, testable models and hypothesis are formulated and later verified to become scientific laws. He placed preference on the latter method. This positivist approach was countered by critical rationalism, a philosophy advanced by Karl Popper who rejected the idea of verification and maintained that hypothesis can only be falsified. Both epistemological philosophies, however, sought to achieve the same objective: to produce scientific laws and theories. The paradigm shift had its strongest repercussions in the sub-field of economic and urban geography, especially as it pertains to location theory. However, some geographers–such as Ian Burton–expressed their dissatisfaction with quantification while others – such as Emrys Jones, Peter Lewis, and Golledge and Amedeo – debated the feasibility of law-making. Others, such as F. Luckermann, criticized the scientific explanations offered in geography as conjectural and lacking empirical basis. As a result, even models that were tested