Multiple sets of documents for different domains may be used to train multiple domain-specific models. A graph model may be generated to include nodes representing concepts included within the domain-specific models. A white space not including any nodes within the graph model may be identified. Analysis of the white space may be performed based on two or more nodes at periphery of the white space. Words/documents that cover the white space may be generated. Novelty of concepts may be readily assessed using the graph model/white space.