Spectroscopic diagnostics play an important role in determining the electron density and temperature structure, element abundances and dynamic nature of different features in the solar atmosphere. To ensure that these techniques are accurate it is necessary to interface solar analysis programs with the best available atomic data calculations. Recent progress in this work is presented and applications to planned space observations are discussed. In particular, the CDS and Sumer instruments, on the Solar Heliospheric Observatory, will make extensive use of spectroscopic diagnostics to study the heating processes for the solar corona and the acceleration mechanisms for the solar wind.