Very-short-answer questions: reliability, discrimination and acceptability
File(s)
Author(s)
Type
Journal Article
Abstract
Context
Single‐best‐answer questions (SBAQs) have been widely used to test knowledge because they are easy to mark and demonstrate high reliability. However, SBAQs have been criticised for being subject to cueing.
Objectives
We used a novel assessment tool that facilitates efficient marking of open‐ended very‐short‐answer questions (VSAQs). We compared VSAQs with SBAQs with regard to reliability, discrimination and student performance, and evaluated the acceptability of VSAQs.
Methods
Medical students were randomised to sit a 60‐question assessment administered in either VSAQ and then SBAQ format (Group 1, n = 155) or the reverse (Group 2, n = 144). The VSAQs were delivered on a tablet; responses were computer‐marked and subsequently reviewed by two examiners. The standard error of measurement (SEM) across the ability spectrum was estimated using item response theory.
Results
The review of machine‐marked questions took an average of 1 minute, 36 seconds per question for all students. The VSAQs had high reliability (alpha: 0.91), a significantly lower SEM than the SBAQs (p < 0.001) and higher mean item–total point biserial correlations (p < 0.001). The VSAQ scores were significantly lower than the SBAQ scores (p < 0.001). The difference in scores between VSAQs and SBAQs was attenuated in Group 2. Although 80.4% of students found the VSAQs more difficult, 69.2% found them more authentic.
Conclusions
The VSAQ format demonstrated high reliability and discrimination and items were perceived as more authentic. The SBAQ format was associated with significant cueing. The present results suggest the VSAQ format has a higher degree of validity.
Single‐best‐answer questions (SBAQs) have been widely used to test knowledge because they are easy to mark and demonstrate high reliability. However, SBAQs have been criticised for being subject to cueing.
Objectives
We used a novel assessment tool that facilitates efficient marking of open‐ended very‐short‐answer questions (VSAQs). We compared VSAQs with SBAQs with regard to reliability, discrimination and student performance, and evaluated the acceptability of VSAQs.
Methods
Medical students were randomised to sit a 60‐question assessment administered in either VSAQ and then SBAQ format (Group 1, n = 155) or the reverse (Group 2, n = 144). The VSAQs were delivered on a tablet; responses were computer‐marked and subsequently reviewed by two examiners. The standard error of measurement (SEM) across the ability spectrum was estimated using item response theory.
Results
The review of machine‐marked questions took an average of 1 minute, 36 seconds per question for all students. The VSAQs had high reliability (alpha: 0.91), a significantly lower SEM than the SBAQs (p < 0.001) and higher mean item–total point biserial correlations (p < 0.001). The VSAQ scores were significantly lower than the SBAQ scores (p < 0.001). The difference in scores between VSAQs and SBAQs was attenuated in Group 2. Although 80.4% of students found the VSAQs more difficult, 69.2% found them more authentic.
Conclusions
The VSAQ format demonstrated high reliability and discrimination and items were perceived as more authentic. The SBAQ format was associated with significant cueing. The present results suggest the VSAQ format has a higher degree of validity.
Date Issued
2018-04-01
Date Acceptance
2017-11-07
Citation
MEDICAL EDUCATION, 2018, 52 (4), pp.447-455
ISSN
0308-0110
Publisher
WILEY
Start Page
447
End Page
455
Journal / Book Title
MEDICAL EDUCATION
Volume
52
Issue
4
Copyright Statement
© 2018 John Wiley & Sons Ltd and The Association for the Study of Medical Education. This is the accepted version of the following article: Sam, A. H., Field, S. M., Collares, C. F., Vleuten, C. P., Wass, V. J., Melville, C. , Harris, J. and Meeran, K. (2018), Very‐short‐answer questions: reliability, discrimination and acceptability. Med Educ, 52: 447-455, which has been published in final form at https://dx.doi.org/10.1111/medu.13504
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000428452400013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Social Sciences
Science & Technology
Life Sciences & Biomedicine
Education, Scientific Disciplines
Health Care Sciences & Services
Education & Educational Research
MULTIPLE-CHOICE QUESTIONS
OPEN-ENDED QUESTIONS
MEDICAL-EDUCATION
CLINICAL COMPETENCE
PROFESSIONAL COMPETENCE
TESTS
STUDENTS
VALIDITY
Publication Status
Published
Date Publish Online
2018-02-01