RESUMO
Objectives: To develop a two-tier diagnostic test in medical education on the analysis of arterial blood gases (ABGs) by students with different background knowledge in anesthesiology, using a concept and knowledge map to determine table of specifications together with an open discussion and a feedback-providing method. Methods: A research and development study in which the developed diagnostic test was assessed for its efficiency by first-year residents, preclinical medical students and nurse anesthetist students who volunteered to join the project. Results: There were four major misconceptions in ABGs: First, they could not clarify the significance and relationship of the symbols. Second, they could not remember the formulas and use them appropriately. Third, they did not understand the analytical steps and lacked knowledge for clinical interpretation. Fourth, they could not apply the logical results as a guideline for patient management. Medical and nurse anesthetist students had problems mainly on the third/fourth misconceptions and partly on the first/second misconceptions. Nevertheless, residents had problems mainly on the fourth misconception and partly on the third misconception. The assessment of criterion-referenced test item difficulty, discrimination and reliability (internal consistency) was 0.59, 0.38 and 0.91 respectively. The item objective congruency (IOC) of the test was equal to 0.88. Conclusions: Using a concept and knowledge map to define the table of specifications in ABGs concepts together with an open discussion and feedback-providing method helped facilitate the scope of developing a two-tier diagnostic more practical test. Teachers can assess misconceptions of students with different background knowledge in a short period of time and have guidelines to improve pedagogy in response to their eagerness for learning.