utility of complex alternatives in multiple-choice items: the case of all of the above

this study investigated the utility of all of the above (aota) as a test option in multiple-choice items. it aimed at estimating item fit, item difficulty, item discrimination, and guess factor of such a choice. five reading passages of the key english test (ket, 2010) were adapted. the test was reconstructed in 2 parallel forms: test 1 did not include the abovementioned alternative, whereas test 2, administered 2 weeks later, included such an alternative. the 2 tests, 32 items each, were administered to 142 high school third-graders. results, analyzed through 3-parameter logistic model, indicated that the multiple-choice questions, including the alternative all of the above, were easier. results also revealed that the option all of the above increased the guess factor. because guess factor is a source of measurement error, it may threaten test validity and reliability.