Interactive training
The classroom interactive training session was conducted as a group for all trainees randomized to this group. The training slides for the NICE classification used in the study were made by Wei-guang Qiao, and the training video was recorded by Yu-tang Ren. Three endoscopists with experience in NBI or BLI for the NICE classification (Si-lin Huang, and Fa-chao Zhi) reviewed the slides and video.For this training, the trainees could review the training slides and the video once. The training slides contained the key factors for diagnosis via the NICE classification, including the color, the vessel pattern, and the surface pattern (Fig. NICE classification. Type 1 featured same or lighter color than background, none or isolated lacy vessels coursing across the lesion with dark or white spots of uniform size, or homogeneous absence of pattern (