Optometry Research Today is a free monthly online journal that collates and summarizes the latest research about Optometry, including details on myopia, optometric practice, therapy.

Comparison of the ASA, MOBS, and ZEST threshold methods.

Anderson AJ, Johnson CA

Department of Optometry and Vision Sciences, The University of Melbourne, 3010, Australia.

The modified binary search, or MOBS, technique is an adaptive, non-parametric procedure for estimating thresholds [Tyrrell, R. A, & Owens, D. A. (1988). A rapid technique to assess the resting states of eyes and other threshold phenomena: the modified binary search (MOBS). Behavior Research Methods, Instruments, and Computers, 20, 137-141.], which has recently been incorporated into a commercially available perimeter. Information regarding the performance of this technique is limited, however. We performed Monte Carlos simulations on the MOBS procedure, as well as on a Zippy Estimation by Sequential Testing, or ZEST, procedure (King-Smith, Grigsby, Vingrys, Benes & Supowit, 1994) and an Accelerated Stochastic Approximation, or ASA, procedure (Kesten, 1958) for comparison. The efficiency, convergence probability, and robustness to false positive and false negative responses were determined. Differences between the three procedures typically were small, the most prominent being the number of presentations required to estimate threshold.

Published 17 April 2006 in Vision Res, 46(15): 2403-11.
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