d and 188 set U=(U-L)/2. Otherwise we consider qo to be below the threshold and set L=(U-L)/2. The 189 algorithm then continues recursively until IL-UI<r, at which point we make the approximation 190 that the threshold occurs at qo=(U-L)/2. 191 EFTA00591454 192 1. Burt, A. Site-specific selfi