Abstract. — Conceptual engineering is the study of how to evaluate and change our concepts, meanings, words, and other representational devices. Experimental philosophy is the use of scientific techniques to collect data on human reactions to central examples in philosophy. One familiar project in conceptual engineering is to address the defects in our concept of truth that cause the liar and other paradoxes by replacing our concept of truth (for certain purposes) with one or more new concepts. I outline a systematic way of identifying potential replacement concepts by using techniques from artificial intelligence. And I introduce a program of experimental philosophy studies to help evaluate which of those potential replacement concepts would be best. The idea is to break down a set of about 50 principles involving truth into the minimal inconsistent subsets and maximal consistent subsets. Then use experimental philosophy to evaluate reactions to each principle. We can use these reactions to measure the plausibility of the replacements because each maximal consistent subset corresponds to a potential replacement concept. Together, conceptual engineering and experimental philosophy can identify the most plausible or highest credence principles involved in a defective concept and measure the overall plausibility of each potential replacement concept by the plausibility of the principles built into it.