When searching in a tree, my understanding of uniform cost search is that for a given node A, having child nodes B,C,D with associated costs of (10, 5, 7), my algorithm will choose C, as it has a lower cost. After expanding C, I see nodes E, F, G with costs of (40, 50, 60). It will choose 40, as it has the minimum value from both 3.
Now, isn't it just the same as doing a Greedy-Search, where you always choose what seems to be the best action?
Also, when defining costs from going from certain nodes to others, should we consider the whole cost from the beginning of the tree to the current node, or just the cost itself from going from node n to node n'?
Thanks
Nope. Your understanding isn't quite right.
The next node to be visited in case of uniform-cost-search would be D, as that has the lowest total cost from the root (7, as opposed to 40+5=45).
Greedy Search doesn't go back up the tree - it picks the lowest value and commits to that. Uniform-Cost will pick the lowest total cost from the entire tree.