This paper defends strict invariantism against some philosophical and empirical data that have been taken to compromise it. The defence involves a combination of a priori philosophical arguments and empirically informed theorizing. The positive account of the data is an epistemic focal bias account that draws on cognitive psychology. It involves the assumption that, owing to limitations of the involved cognitive resources, intuitive judgments about knowledge ascriptions are generated by processing only a limited part of the available information—the part that (...) is in focus. According to the epistemic focal bias account, the intuitive judgments about knowledge ascriptions that constitute contrast effects amount to false positives, whereas the intuitive judgments that constitute salient alternatives effects amount to false negatives. I conclude by considering how the basic epistemic focal bias account may be developed further by reference to relevant alternatives theory in epistemology, pragmatics in the philosophy of language, and dual process theory in cognitive psychology. (shrink)