  This paper reports on the statistical behaviour of the optical IntraDay
Variability of BL Lac S5 0716+714. Available IntraDay Variability data in the
optical is tested to see whether or not the magnitude is log-normally
distributed. It was consistently found that this is not the case. This is in
agreement with a previous discussion for data for the same object but in a
different observational period. Simultaneously, the spectral slope of the light
curves is calculated. The implications of these findings for models which
discuss both the location and the source of IntraDay Variability are presented.
