Some Question about the Papar

[CreatorZZY]

I am sorry, but i meet a problem while i watch your Paper: <Disease State Prediction From Single-Cell Data Using Graph Attention Networks>.
Both of the Problems is at here:

1. What the output(scores) of Different head or Each head can tell you? In my opi, that just is the feature, is the output of the Black box. I can't guess what information it can tell you(Although I have seen your results with Heatmap).
2. Can you have a brief Explanation of the "a sparse version"? Pleaseesesesese