 Contextualists have modeled this context-sensitivity in various ways. Keith DeRose 2009 has suggested that there is a context-invariant notion of “strength of epistemic position”, and that how strong a position one must be in in order to satisfy “knows” varies from context to context; this is in effect to understand the semantics of knowledge attributions much as we understand that of gradable adjectives. (How much height one must have to satisfy “tall” also varies from context to context.) Cohen 1988 adopts a contextualist treatment of “relevant alternatives” theory, according to which, in skeptical contexts, but not ordinary ones, skeptical possibilities are relevant. This aspect is retained in the view of Lewis 1996, which characterizes a contextualist approach that is more similar to quantifiers and modals. Blome-Tillmann 2009b and Ichikawa forthcoming-a defend and develop the Lewisian view in different ways.