Recent crystallographic work in several groups have demonstrated that electron optical methods are viable options for structure solution over a wide field, including various kinds of inorganic structures, small organic molecules, biological macromolecules, organic polymers. Successful refinement has been obtained from intensity data collected by selected area electron diffraction (SAED) or micro-diffraction. Refinement of structure factor amplitude and phases to very high accuracy has been attained by the convergent-beam (CBED) technique for crystals with small unit cells. The main advantage of electron crystallography remains the facility to study minute crystals, and to relate these to their surroundings, e.g. in multiphase materials. Other benefits include sensitivity to ionic states, bond charges and charge fluctuations; combination with other electron microscopy techniques, such as spectroscopy with high spatial resolution. The problems and tasks one is facing in development of the field have two main aspects. One needs to:

1. establish reliable, well-documented procedures, that extend from data collection, through workable procedures for determination and verification to satisfactory refinement of crystal structure. The difficulties, (especially related to dynamical scattering effects) must be dealt with - and the specific advantages exploited.
2. focus on classes of structure problems that depend upon electron crystallographic methods for satisfactory solutions. Flexibility and variations in the method is expected to remain a characteristic feature of electron crystallography. Combination with other crystallographic technique, such as X-ray powder diffraction, will increase. Other aspects besides precision in position parameters may be brought into focus, e.g. ionicity of the atom species, disorder and defects.