6. A computer-implemented method comprising: receiving, at one or more computers comprising at least one processor and at least one memory, a definition of a perspective into a dataset associated with N separate ontologies that each specify relationships among data elements in the dataset, wherein N is greater than two, the N separate ontologies correspond to an N dimensional information space, and the data elements are placed in the N dimensional information space according to semantic similarity among ontology elements, wherein the number N of dimensions in the information space matches up with the number N of the separate ontologies; reducing, at the one or more computers, the N dimensional information space to X dimensions based on the perspective definition, wherein X is greater than one and less than the perspective comprises a projection from the N-dimensional space to the X-dimensional space, and the perspective definition defines a mapping from original N axes to target X axes, the perspective definition being denotable as P N→3 =(F 1 (DS 1 ), F 2 (DS 2 ), F 3 (DS 3 )), where P N→3 represents a perspective that maps information from N-dimensional space to 3-D space, F i represents mapping functions from original N-dimensional axes to a target i-th axis, and DS i represents original axes that participate in a transformation; and presenting a visual representation of the dataset in the X dimensional space.
6. A computer-implemented method comprising: receiving, at one or more computers comprising at least one processor and at least one memory, a definition of a perspective into a dataset associated with N separate ontologies that each specify relationships among data elements in the dataset, wherein N is greater than two, the N separate ontologies correspond to an N dimensional information space, and the data elements are placed in the N dimensional information space according to semantic similarity among ontology elements, wherein the number N of dimensions in the information space matches up with the number N of the separate ontologies; reducing, at the one or more computers, the N dimensional information space to X dimensions based on the perspective definition, wherein X is greater than one and less than the perspective comprises a projection from the N-dimensional space to the X-dimensional space, and the perspective definition defines a mapping from original N axes to target X axes, the perspective definition being denotable as P N→3 =(F 1 (DS 1 ), F 2 (DS 2 ), F 3 (DS 3 )), where P N→3 represents a perspective that maps information from N-dimensional space to 3-D space, F i represents mapping functions from original N-dimensional axes to a target i-th axis, and DS i represents original axes that participate in a transformation; and presenting a visual representation of the dataset in the X dimensional space. 9. The method of claim 6 , wherein the data elements are placed in the N dimensional information space by a process comprising determining distances among the data elements with respect to a given ontology based on a tree structure of the given ontology and estimates of co-relation between the ontology elements of the given ontology, wherein the estimates are based on a corpus including data elements associated with the ontology elements and documents retrieved from a computer network in accordance with terms retrieved from the data elements associated with the ontology elements.