Guessing is a standard test-taking strategy presented to examinees taking a multiple choice assessment. The current research examines the guessing and omission behaviors and effects on scores from actual administrations of an operational computerized adaptive test. The probability of observing score differences when items at the end of the test are omitted or guessed are based on examinee behaviors. Furthermore, differences were examined for both verbal and quantitative sections to determine whether results are consistent across section types.