This work addresses an important problem in industry -locating the bottleneck in a production line -and suggests a practical approach to accomplish that end. We describe and validate, using discrete event simulation, a novel method of bottleneck detection in open, asynchronous serial production lines with finite buffers. The technique uses a single measure -station interdeparture time variance -to locate the system bottleneck. The proposed method is compared to other bottleneck detection approaches and it is shown that the proposed method performs as well and sometimes better than other methods. We conclude that the proposed approach has a number of significant advantages. It is easy to use and implement, not requiring data about failure and repair times, raw process times, buffer sizes, etc., but instead uses a single piece of easily obtained real-time production line data -station work-in-process (WIP) interdeparture time. The proposed method can identify production constraints without the need to build an analytical or simulation model, is well suited for use in industry, and can be readily implemented in standard simulation tools.

In the administration and interpretation of WISC R profiles of children with high IQs (124+), clinicians may be misled if they follow the standard rules for subtest substitution and omission or use the standard "frequen cy of Verbal-Performance discrepancy" tables. Although . such tables are accurate for the "average" child, they greatly overestimate the rarity of rarity of V-P discrepancies in high IQ children (over half of whom show a V-P discrepancy larger than 15 points). To lend greater accuracy to the interpretation of WISC-R profiles of high IQ children, a specialized table is provided for determin ing the frequency of occurrence of V-P discrepancies in profiles of high IQ children and warnings are offered regarding the adverse effect of subtest substitution or omission when administering the WISC-R to high IQ children.

The Learning Disability Index (LDI) was validated by an examination of the mean profiles and demographic characteristics of high and low LDI subsets of the standardization sample of the Wechsler Intelligence Scale for Children-Revised. The LDI continuum, however, was found to measure Third Factor strengths/weaknesses as much as verbal-performance discrepancies.

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We examined the demographic distribution of 102 subjects with attention deficits in the Wechsler Intelligence Scale for Children-Revised (WISC-R) (Wechsler, 1974) standardization sample. Neither age nor occupational status was significant; males were overrepresented (3:1); and the West was overrepresented by 50%, largely due to the relatively high proportion of females in the West who appeared within the attention deficit sample (41% in West vs. 19% in the rest of the nation). Replication is encouraged.