Radiocarbon dating was introduced in 1946 by W. F. Libby, who was recognized with a Nobel Chemistry Prize fourteen years later (1960). From the beginning, many variables which should be considered in using the technique were recognized, several by Libby and his co-workers: 1) cosmic ray flux through the atmosphere 2) C-14 concentration in the ocean and atmosphere 3) C-14 decay half-life 4) Migration of carbon atoms into or out of earth materials 5) Local variation in carbon isotope concentrations, called fractionationThese variables will be discussed briefly from the viewpoint of creationist contributions to the subject.