PURPOSE This study investigated differences in gaze entropy according to skill level and temporal occlusion in table tennis serve reception. METHODS Study participants were divided into a skilled group (n = 6) and a novice group (n = 6). The study task involved sitting in front of a monitor while wearing an eye tracker, watching 36 serve videos, and predicting whether the ball’s length would be short or long by pressing the "Top" (short serve) or "Bottom" (long serve) pad on the selection response pad. RESULTS Overall, the later the temporal occlusion level, the faster the reaction time and the higher the judgment accuracy. At temporal occlusion levels 2 and 3, skilled participants showed higher judgment accuracy than novices. Analysis of heatmap and gaze entropy revealed that novices exhibited visual search toward the ball across all temporal occlusion levels (T1, T2, T3) and had high gaze entropy. In contrast, skilled participants generally showed visual search to the racket area depending on the temporal occlusion level, with low gaze entropy at T1 and T2, and a tendency for increased gaze entropy at T3. CONCLUSIONS Compared to novices, skilled participants had lower gaze entropy and fixated more on the racket area when predicting table tennis serves. Similarly, novices focused more on the ball than on the racket. The study also proposed the value of using heatmap and Shannon entropy for this type of analysis.
