The focus of this article is on the design and administration of an online computerized dynamic assessment of an important area of pragmatics: implicature comprehension (i.e., indirect meaning). The assessment centered on indirect acceptances, refusals, and opinions. Drawing on Vygotskian psychology, this assessment had a dual aim: (a) to evaluate test-takers' current capacities as evidenced by independent performance and (b) to evaluate test-takers' emerging capacities as evidenced by their responsiveness to assistance, or mediation, during the test. Sixty-seven US university learners of Chinese as a foreign language, evenly distributed across beginning, intermediate, and advanced course enrollment levels, took the assessment. The results show that while all test-takers were able to improve with assistance, there was a large degree of individual variation in responsiveness to mediation. In line with the notion of the zone of proximal development, we interpret our findings as evidence that the performances observed with mediation are more informative as a diagnosis of learner capability than independent performance alone. Our discussion therefore focuses on the implications of our testing approach for developing individual teaching and learning plans for test-takers, as well as directions for future research.