Abstract
The use of the classical path approximation in line broadening theory is illustrated in a development of the familiar impact and one-electron theories. The one-electron theory which is presented is an improved version of the usual one-electron theory; this improved version of the theory provides a consistent description of a line profile from the halfwidth to the quasi-static wings. The validity criteria for the impact and one-electron theories are discussed in detail and a comparison of the theories is made with a view toward the development of a more general theory containing elements of both. To avoid unnecessary mathematical complications and to provide a more transparent comparison of the theories, the Stark broadening of the Lyman series in hydrogen is used as a specific example.