This programmed text of self-instruction is one of a series of manuals on techniques describing procedures for planning and executing specialized work in water-resources investigations. It has been prepared on the assumption that the reader has completed standard courses in calculus and college physics and is presented in eight parts. Part I introduces some fundamental hydrologic concepts and definitions. Part II discusses Darcy's law for unidirectional flow. Part III considers the application of Darcy's law to some simple field problems. The concept of ground-water storage is introduced in Part IV. A text-formal discussion at the beginning of Part V deals with partial derivatives and their use in groundwater equations; the basic partial differential equation for unidirectional nonequilibrium flow is developed in the programmed material of Part V. In Part VI, the partial differential equation for radial confined flow is derived and the "slug-test" solution, describing the effects of an instantaneous injection of fluid into a well, is presented and verified. Part VII introduces the general concepts of finite-difference analysis. Part VIII is concerned with electric-analog techniques. (HD)