This paper concerns the central method of generating evidence in support of contextualist theories, what we call context shifting experiments. We begin by explaining the standard design of context shifting experiments, which are used in both quantitative surveys and more traditional thought experiments to show how context affects the content of natural language expressions. We discuss some recent experimental studies that have tried and failed to find evidence that confirms contextualist predictions about the results of context shifting experiments, and consider (...) the criticisms of those studies made by DeRose (forthcoming). We show that DeRose's criticisms are incomplete, and we argue that the design of context shifting experiments he proposes is itself subject to some of the same problems as the studies he criticizes. We propose a refined approach to the design of context shifting experiments that addresses these problems and which allows us to to investigate the effect of context on both positive and negative sentences. This aspect of our design allows us to control for several forms of bias, including a particular form of "truth bias" that favors positive over negative sentences. We then deploy our improved design in an experiment that tests a large number of scenarios involving different types of expressions of interest to contextualists, including "know" and color adjectives like "green". Our experiment (i) reveals an effect of changing contexts on the evaluation of uses of the sentences that we examined, thereby overturning the absence of results reported in previous experimental studies (so-called null results) and (ii) reveals previously unnoticed distinctions between the strength of the contextual effects we observed for scenarios involving knowledge ascriptions and for scenarios concerning color and other miscellaneous scenarios. (shrink)