This section describes the ``Method 1'' algorithm which has been installed to compute optical parameters from the basic information provided above. The philosophy of this approach is to break the problem down into separate tasks, each of which addresses a particular aspect of the calibration. Emphasis is placed on comparisons between relative quantities in an attempt to make the results as independent of specific detector geometry as possible so that they will be robust in the face of uncertainties in source placement etc. The derivation of all quantities described requires a minimum of 4 laserball positions: 2 inside the AV along the vertical detector axis, and 2 in the light water region between the AV and PSUP. In addition, one of the inside positions must be located near the center of the detector. The order in which the following tasks are carried out is important.