Inclusive Asymmetries and Spin Structure Functions of the Nucleon

Over the past 25 years, an impressive data set on the inclusive double spin asymmetries A₁(Q², x) and A₂(Q², x) has been collected at many labs worldwide, including SLAC, CERN, HERA, JLab, and MAMI. Many more experiments are underway or in various stages of preparation. The large kinematic range of the existing and anticipated data, from the real photon point Q² = 0 to the scaling region and from elastic scattering to the DIS regime, allows us to study many questions at the forefront of hadronic physics. Among these are the valence quark, sea quark and gluon structure of the nucleon, the transition from quark degrees of freedom to hadronic ones (including quark-hadron duality), perturbative and higher twist scaling violations, and the validity and convergence of several fundamental sum rules. This paper contains an overview of the status and results from existing experiments and gives an outlook of what we can expect from new programs now underway.