DECISION TREE QUESTONS!?

ndf-ls

Hey Guys,
another quick question:
In the decision-tree-operator, i can determine which attributes should be chosen first for growing the tree. These are:
- gain_ratio
- information_gain
- gini_index
- accuracy

However, i do not really unterstand these settings. Can anyone describe these in detail?!
My second question refers to the Subtrees and leaf-details. When you are in the results-view and stay on one leaf (or node) with the curser for some seconds, you get detailed information about the leaf. Is there a possibility to show these details straight away in all the leafs and pemanently?!

Thank you very much in advance,
Leo