AbstractResearch has shownthat a given core quantity appears larger as contextual stimuli become smaller, and conversely. This study sought to determine whether such contextual effects are greatest where contextual stimuli appear highly relevant in assessing a core quantity. As defined here, contextual relevance hinges upon physical similarity between core and context objects, as well as upon certain canons of appropriate judgment behavior such as the scientific method.Two parallel experiments were conducted. In both studies, reducing contextual magnitude increased the apparent size of core quantities, as predicted, where contextual relevance was high. Further, such increases in judged core‐quantity magnitude had predicted effects on perceived writer stand (pro or con).Where contextual relevance was low, increasing size of context did not influence perceived magnitude of the core quantity viewed in isolation. Here, apparently, respondents discounted low‐relevant contexts as predicted. However, when judging author stand on an issue, respondents apparently tended to rate a core quantity as large where context was large and of low releva