Effects of signal uncertainty on statistical decisions

The experimental task involved statistical judgements about parameters of a random sample of dots displayed sequentially from a ‘signal’ or ‘noise’ distribution. Signal uncertainty was introduced by presenting small signal subsets of dots within larger observation sequences. Observer detection performance was adversely affected by this kind of signal uncertainty, but in the same way and to similar extent as that expected on the basis of ‘ideal’ and ‘independent’ statistical decision strategies.