I am becoming curious about how psychiatrists measure their respective patients' I.Q.s. In clinical psychology we rely heavily on vocabulary. This method seems tried and trued: 1.) I have seen research that highly correlates IQ to vocab, 2.) On every WAIS-R which I have administed, their score on the vocabulary portion of the test was pretty much commensurate to their full scale IQ, whereas poor performance on other sections of the WAIS-R could not always be used to project full scale IQ. However, are there other ways you use to estimate IQ?