Reliability of physiology MCQs’ examinations at the Faculty of Medicine, University of Khartoum

Afraa M.M. Musa


One of the major challenges that face exam constructors is generating highly reliable exams. An assessment cannot
be viewed as valid unless it is reliable. Test reliability, which is the best single measure of test accuracy, is
the extent to which test results are consistent, stable, reproducible and free of error variance. Reliability is
influenced by internal factors related to exam construction, as well as external factors which depend on the
situation of test administration.
To estimate the reliability of multiple choice questions (MCQs) of physiology exams as part of an overall
quality assessment at the Faculty of Medicine, University of Khartoum.
Reliability influential factors related to exam construction and administration were controlled and catered
for by departmental and administrative staff according to the exam regulations of the faculty. Remark
software was used for post-examination analysis of scores of ten consecutive summative physiology MCQ
exams at the Faculty of Medicine, University of Khartoum. The number of the examinees who sat for each
of the ten exams ranged from 332–359. In addition to reliability coefficients, item difficulty index (DIF I)
and point-biserial correlation coefficient (rpbis) as a measure of item discrimination ability, were calculated
as part of item analysis results.
The study revealed high exams’ reliability (0.84-0.95) as measured by different formulas [Kuder-Richardson
Formulas (KR-20, KR-21) and Cronbach’s-Alpha], and low standard error of measurement/SEM (3.07-
3.80). Factors which contributed to the high reliability of our ten exams were: their high discrimination
power (0.32-0.47), their recommended mean difficulty (48.62-65.67%), and the relatively large numbers of
items (60–80) per each exam.
The high exams reliability of this study was an indicator of the precise control of external and internal
factors influencing reliability. The most important contributing factor was the proper construction of exams
with high quality items; in addition to careful exam administration and meticulous scoring system.
*Corresponding author: Department of Physiology, Faculty of Medicine, University of Khartoum, Sudan

Full Text:



  • There are currently no refbacks.

ISSN: 1858-5345