Effects of text difficulty and adults' age on relative calibration of comprehension.

Weaver and Bryant (1995) proposed the optimum effort hypothesis, suggesting that undergraduate students were better able to predict comprehension when text materials matched their reading level (grade 12) as opposed to being too easy or too difficult (Weaver and Bryant did not assess the actual reading level of their participants). In the study, we examined the reading level and accuracy of performance prediction of both younger and older adults using Weaver and Bryant's materials. Regardless of our participants' high reading levels (grade 14 and above), they still predicted performance best when texts were written at around the grade 12 level, failing to support the optimum effort hypothesis.