A magnetic material must first be grown in a form appropriate for the measurement — crystalline or amorphous, bulk, thin film or particulate, and characterized structurally by X-ray or electron diffraction. Central to most magnetic measurements is the generation and detection of magnetic fields. Atomic-scale magnetic structure is best probed by neutron diffraction, while other atomic-scale element-specific information is provided by spectroscopic methods, especially using synchrotron radiation. Domain-scale magnetization measurements are made by magneto-optic methods or magnetic force microscopy, whereas macroscopic measurements of magnetization are made in open or closed circuit by a variety of methods. Spin-wave and other excitations are best explored by inelastic neutron scattering. Numerical methods of investigation are of growing importance for understanding the static and dynamic behavior of real magnetic materials and magnetic systems.