The reported study compared the instructional effectiveness of Modern English explanatory interpretations of Shakespearean play extracts integrated line by line into original Elizabethan English text, with a conventional unguided original text condition. Experiment 1 demonstrated that the explanatory notes group reported a lower cognitive load and performed better in a comprehension test than the control group when students had no prior knowledge of the text. In Experiment 2, a reverse effect occurred when the same material was presented to a group of Shakespearean experts. Experiment 3 replicated the results of Experiment 1 using a different Shakespearean play. The study demonstrated that the relative effectiveness of instructional conditions depended on learner levels of expertise. In accordance with the expertise reversal effect, the benefits of guided instruction reversed and became detrimental for learners with high prior knowledge levels. Retrospective verbal protocols indicated that the explanations were redundant for expert readers.