Endotracheal intubation and mask ventilation procedural skills are basic skills which have to be learnt by medical student and have to be practiced directly. However, during COVID-19 pandemic, offline training was difficult to be conducted and new specific learning method has not established yet. The study aims to assess the effectiveness of modified Peyton's four-step approach, which can be implemented through online training, compared to the classic Peyton's four-step approach in learning endotracheal intubation and mask ventilation procedural skills.

Inclusion Criteria:

• Preclinical students of Faculty of Medicine Universitas Indonesia agreed to participate and signed the consent
• Preclinical students of Faculty of Medicine Universitas Indonesia registered to attend every training session of endotracheal intubation and mask ventilation under Basic Clinical Skills module
• 100% attendance in every session

Exclusion Criteria:

• Students who have attended endotracheal intubation and mask ventilation training beforehand
• Students who have learnt endotracheal intubation and mask ventilation under Basic Clinical Skills module beforehand

Drop out Criteria:

• Preclinical students of Faculty of Medicine Universitas Indonesia who quit from Basic Clinical Skills module during research
• Students who have never attended the training session