Objective To investigate the effect of group feedback and formative assessment respectively on teaching effectiveness of endotracheal intubation (ETI). Method After a theoretical lecturing and theoretical test

Eighty three undergraduates were randomized into concurrent-feedback group and group-feedback group. ETI simulation training was given respectively by providing concurrent or group feedback in the two groups

and then undergraduates received a skill assessment. After a theoretical lecturing and theoretical test

other 91 undergraduates were randomized into final-assessment group and formative-assessment group. ETI simulation training and skill assessment were given in final-assessment group. Before training

first skill assessment was performed in formative-assessment group

and then feedback was delivered based on the assessment. After training

second skill assessment was given again. Skill assessment was evaluated using the criterion-based task specific checklist combined with global rating scale. T-test was used for comparison between groups. Results There is no statistical difference (P=0.212) in theoretical scores between group-feedback group (39.1±2.5). and concurrent-feedback group (38.2±3.8). Skill assessment score of group-feedback group (39.4±4.9) was higher than that in concurrent-feedback group (35.4±4.6)

with statistical difference (P＜0.001). There is no statistical difference (P=0.395) in theoretical scores between formative-assessment group (41.1±4.0) and final-assessment group (40.2±5.6). Score of formative-assessment group (39.4±4.9) was higher than that in final-assessment group (35.4±4.6)

with statistical difference (P＜0.001). Conclusion Terminal feedback or formative assessment could enhance teaching effectiveness of endotracheal intubation among medical students.