This study examined how, and under what conditions, teacher clarity (i.e., structure/signaling) impacts student learning. One hundred and forty eight students reported their propensity to approach their studies with a mastery orientation and were randomly exposed to a lesson on persuasion that was either signaled or not. After the lesson, students reported the extent to which they were able to organize the information in a coherent manner and took a test of their cognitive learning. Results indicated that, compared with the unsignaled lesson, students exposed to the signaled lesson scored higher on a test of cognitive learning to the extent that they were able to organize information meaningfully. However, the indirect effect of signaling on learning through organization was only evident for students who scored low on a measure of mastery orientation. Results are discussed as they pertain to our knowledge of clear teaching and the generative process of student learning.