The various methods to acquire knowledge are the basis of alternative models of science. With regard to science, one may speak of models in different senses, but the two main ones are models of science and models in science. Models of science are representations of how scientists build their theories. The chapter considers four models of science: the analytic-synthetic model, the hypothetico-deductive model, the semantic model, and the analytic model. Models in science are representations of empirical objects, phenomena, or processes of some area of science. The chapter discusses to what extent each of the above four models of science is capable of accounting for models in science.