Reid (1968) studied the effects of
grammatical complexity and compressed
speech on comprehension. He used a form of
the Nelson-Denny Reading Test to make two
difficulty levels of grammatical complexity and
compressed speech at 175, 275, 325, and 375
wpm. Further, the Verbal Scholastic Aptitude
Test was used as a covariate. Results suggest
a significant main effect for both compressed
speech and grammatical complexity and a
significant interaction effect. Compressed
speech was not statistically significant until 375
wpm level, which is more than double the speed
of normal speech.