Features
Personalization Actions: PIBE browsing facilities offer the user powerful ways to explore the BT to look for images of interest. However, the initial BT (which is built in an automatic way by means of a clustering algorithm) may not reflect the meaning that different users may attach to clusters and individual images. To bridge such semantic gap, PIBE also provides a number of actions that a user can perform to adapt the initial BT to his/her current preferences (we call the personalized tree custom BT).
The rationale behind personalization actions is as follows:
When a node of the BT is not semantically related to its parent, the user may want to move the entire node subtree to a different part of the BT (Fusion action);
when sibling nodes are not semantically related to each other (thus their parent node cannot be considered as an appropriate generalization of them), he/she may want to drop the parent node and substitute it with two or more selected children (Split action);
when a BT node is too specialized, and the user want to reduce the number of its children (Merge&Divide action).
To give an example, following figures make evident that, at each level of the tree, the custom BT provides the user with more informative representative images than the initial BT, simplifying the user search task when searching a "shark" and a "blowfish", respectively (we highlight with a red square nodes that are explored by means of vertical browsing).
