The paper provides a brief overview of its content and highlights its contributions compared to previous work. It compares different instructions and demonstrates the use of fret highlighting and a virtual hand on both desktop and augmented reality (AR) platforms. One notable contribution is the inclusion of head-mounted displays (HMDs) for AR.
What I like about the paper is that it clearly shows the superiority of HMD/AR cues, which have practical applications right now.
However, one aspect that I think could have been improved is the design of the fret markers. It would have been better if the design conditions, such as colors, were as similar as possible across different conditions.
As for what should be done next, it would be interesting to explore cues other than visual aids. For example, a wearable glove that provides physical cues to each finger could be developed. This could help with muscle memory and enhance the learning experience.