Computer-based tests administered in established commercial testing centers typically have used monitors of uniform size running at a set resolution. Web-based delivery of tests promises to greatly expand access, but at the price of less standardization in equipment. The current study evaluated the effects of variations in screen size, screen resolution, and presentation delay on verbal and mathematics scores in a sample of 357 college-bound high school juniors. The students were randomly assigned to one of six experimental conditions—three screen display conditions crossed with two presentation rate conditions. The three display conditions were: a 17-inch monitor set to a resolution of 1024 x 768, a 17-inch monitor set to a resolution of 640 x 480, and a 15-inch monitor set to a resolution of 640 x 480. Items were presented either with no delay or with a five-second delay between questions (to emulate a slow Internet connection).
No significant effects on math scores were found. Verbal scores were higher, by about a quarter of a standard deviation (28 points on the SAT® scale), with the high-resolution display.