This study explored the various adjusting procedures for minimizing the size of gaps resulting from the raw-to-scale score conversions under test forms that varied in difficulty. The no adjustment, the fixed mean, the varying mean, and the varying mean/SD approaches were compared using the data simulated based on the three-parameter extended beta-binomial model for the five tests in the Basic Competence Test (or BCTEST) administered from 2001 to 2003. The BCTEST is a national standardized assessment in Taiwan and the forms of each of its tests varied slightly in difficulty over these years. The desired gap sizes were set at 3, 4, and 5 scale score points at the high end of the scale. The criteria for comparing the adjusting approaches over the years were by means of the summary statistics, reliability, overall SEM, SEMs by true score in proportion-correct score units, and the number of scale score points changed due to the truncation as well. The results showed that test form difficulty affected the performance of the various adjusting procedures to some extent and no one method could accomplish the goal of reducing the gap sizes at the upper end without negatively affecting the other scale score attributes. Imposing adjustments on the gaps at the high end of the scale would exert more effects on the easier forms than on the harder forms. The impact due to adjustments decreased as the forms increased in difficulty. Overall, the varying mean/SD strategy was judged the most preferable. Findings from this research have fostered the understanding of the gaps issue and have raised greater awareness of the role that test form difficulty plays in establishing the score scales.