Report Example on Item Analysis: Validity, Reliability, and More

An item analysis is a critical step in developing any test, whether academic examinations, diagnostic tools, or research items. It is a process that seeks to gauge the quality of an item in a test concerning the attainment of its desired purpose. Within this process, an item can either be included in the final test or dropped. Understanding the criteria for retaining or dropping test items is thus critical.

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An item analysis is based on five indicators: validity, reliability, difficulty or easiness indices, discrimination index, and distracter effectiveness. Therefore, when conducting an item analysis, these five indicators must be considered in determining whether to drop or include an item. Validity refers to the extent that an item measures what it is supposed to measure, and how well it attains this purpose (McCowan & McCowan, 1999). On the other hand, reliability is a measure of test accuracy, and these include its stability, consistency, and freedom from error, even when re-administered. Another indicator is the degree of easiness or difficulty of an item, the discrimination index between two extreme ends of the outcome, and the distracter effectiveness, which is the participants' ability to point out the correct answer from the plausible but incorrect one(Arora, 2018). Using these indicators, it is possible to single out items that are unsuitable for a particular test.

When considering dropping an item from a test, the first two traits would be its invalidity and unreliability. Apart from the two, there are other traits. Item difficulty or easiness, often referred to as the p-value, is one of these traits. P-value for items often range from 0.0 for difficulty, to 1.0 for easiness. When considering criterion-referenced tests that seek to gauge mastery of content, the p-value will be .9 or above. This value will be between .4 and .5 (Professional testing Inc., 2006) for norm-referenced tests. Therefore, any items with values lower or higher than these must be dropped. As for test discrimination, the point-biserial correlation must be within the range of -1.0 to 1.0. An item with any other value must be dropped. A distractor analysis is usually used to determine the distractibility of a test item. An item must have a distractible index where the other options are incorrect and plausible. The presence of two correct answers, for instance, could be a cause to drop an item.

Conclusion

Item analysis is crucial in ensuring that test items are valid, reliable, and relevant. A failure to conduct an item analysis on a qualitative or quantitative test renders it ineffective. When this happens in an examination, this means that the academic evaluation fails to attain its mandate. When it is a diagnostic tool, it means a patient will be misdiagnosed, resulting in detrimental health impacts.

References

Arora S. (2018). Item analysis. International Journal of Nursing Science Practice and Research, 4(2). Pp. 6-7. Retrieved from https://www.researchgate.net/publication/327906979_Item_Analysis

McCowan R. J. & McCowan S. C. (1999). Item Analysis for Criterion-Referenced Tests. Center for Development of Human Services. Pp. 1-39. Retrieved from https://files.eric.ed.gov/fulltext/ED501716.pdf

Professional testing Inc. (2006). Test topics. Retrieved from http://www.proftesting.com/test_topics/steps_9.php