This part of 15367 specifies methods for measurement and evaluation of the wavefront distribution function in a transverse plane of a laser beam utilizing Hartmann or Shack-Hartmann wavefront sensors. This part of 15367 is applicable to fully coherent, partially coherent and general astigmatic laser beams, both for pulsed and continuous operation.Furthermore, reliable numerical methods for both zonal and modal reconstruction of the two-dimensional wavefront distribution together with their uncertainty are described. The knowledge of the wavefront distribution enables the determination of several wavefront parameters which are defined in 15367-1.