Box 6 in Chapter 3 gives estimates for gains over time on certain WISC and WAIS subtests and projects those gains into the future (up to 2012). It is derived from four tables.

(1) Table AI1 gives WISC gains on all subtests from the WISC (1947.5) to the WISC-IV (2001.75). Table AII3 in Appendix II adds detail on the calculations.

(2) Table AI2 uses past trends to project the gain from the WISC-IV to the “WISC-V” on the assumption that the latter will be normed in 2012. This entails pro-rating all subsequent trends over the interval of 24.5 years that separated the norming of the WISC and WISC-R. All calculations are explained at the bottom of the table. The final column gives what I think the actual Scaled Score gains (SD = 3) will be from the WISC-IV to the WISC-V, just for fun. To get the modern age values in Box 6 , average the four Modern world values numbered (1) to (4) respectively.

(3) Table AI3 gives WAIS gains on all subtests from the WAIS to the WAIS-IV. Table AII2 in Appendix II adds detail on both scores and calculations.

(4) Table AI4 uses past trends to project the gain from the WAIS-IV to the “WAIS-V” on the assumption that the latter will be normed in 2016. This entails projecting all subsequent trends over the interval of 24.5 years that separated the norming of the WAIS and WAIS-R. All calculations are explained at the bottom of the table. The final column gives what I think the actual Scaled Score gains (SD = 3) will be from the WAIS-IV to the WAIS-V, just for fun. To get the modern age values in Box 6 , average the four Modern World values numbered (1) to (4) respectively.