Scandium weighted oscillator strengths gf for the 677 transitions in the NIST database as a function of our calculated values. Filled and open symbols refer, respectively, to transitions that are observed, or not observed and predicted from two observed levels. NIST has no oscillator strength for Sc xxi and Sc vi. The two grey lines delineate the values gf_NIST/gf_FAC = 2 or 1/2.