In this talk the indicativity account of knowledge is applied to the problem of perceptual skepticism, and in particular to the retraction phenomenon, which involves the reaction of the subject to a skeptical challenge, whereby the subject retracts her earlier assertion. A cognitive explanation of the retraction phenomenon is offered, with no appeal to threshold volatility, thereby offering an alternative account of perceptual skepticism and, more specifically, of the retraction phenomenon, to that of contextualism. Along the way a methodological conception of conceptual analysis as a simulation model is presented, which is employed in the explanation of the retraction phenomenon. Different notions of assertibility are presented, which are natural derivatives of the indicativity account of knowledge, and which are useful for the analysis of perceptual skepticism and the retraction phenomenon. The more important among them reflects an internalist norm of assertion. The contrast to the contextualist approach is presented primarily as involving the stability (as opposed to the volatility) during the encounter with the skeptic of the threshold as well as of the truth conditions of knowledge ascriptions, as well as of various notions of assertibility. The account presented here brings out the diversity of appropriate responses to the skeptical challenge in different sub-cases of, e.g., the zebra/painted-mule case.