A discussion on the determination of effective temperature (Teff) and surface
gravity (log g) is presented. The observational requirements for
model-independent fundamental parameters are summarized, including an
assessment of the accuracy of these values for the Sun and Vega. The use of
various model-dependent techniques for determining Teff and log g are outlined,
including photometry, flux fitting, and spectral line ratios. A combination of
several of these techniques allows for the assessment of the quality of our
parameter determinations. While some techniques can give precise parameter
determinations, the overall accuracy of the values is significantly less and
sometimes difficult to quantify.Comment: 10 pages, 5 figures. To appear in the proceedings of the Workshop
"ATLAS 12 and related codes", Trieste, July 11-15, 200
