Evaluating distinctiveness of document

A method of evaluating a degree of distinctiveness of each combination of terms contained in a target document including at least one document segment with respect to a comparison document including at least one document segment, the method comprising:

• (a) identifying a respective document segment vector for each document segment contained in the comparison document and the target document, each document segment having component values associated with occurring frequencies of terms occurring in the document segment;
• (b) from the document segment vectors, computing squared sum matrices respectively corresponding to the comparison document and the target document;
• (c) computing a predetermined number of orders of topic difference factor vectors of the target document from the squared sum matrices respectively corresponding to the comparison document and the target document;
• (d) computing values of inner products for each of said document segments of the target document and the comparison document, said values of inner products being calculated between the corresponding document segment vector and the topic difference factor vectors of the respective orders;
• (e) computing degrees of distinctiveness of said respective orders and a total degree of distinctiveness for each combination of terms contained in the target document, on the basis of correlation coefficients between frequencies of each combination of terms in the respective document segments and the values of the inner products;
• and
• (f) transmitting an output to a device wherein the output comprises the computed degrees of distinctiveness of at least one of said respective orders and a total degree of distinctiveness for each combination of terms contained in the target document.

A method of evaluating a degree of distinctiveness of each term contained in a target document including at least one document segment with respect to a comparison document including at least one document segment, and identifying a distinctive term, the method comprising:

• (a) identifying a respective document segment vector for each document segment contained in the comparison document and the target document, each document segment vector having component values associated with occurring frequencies of terms occurring in the document segment;
• (b) from the document segment vectors, computing squared sum matrices respectively corresponding to the comparison document and the target document;
• (c) computing a predetermined number of orders of topic difference factor vectors of the target document from the squared sum matrices respectively corresponding to the comparison document and the target document;
• (d) computing values of inner products for each of said document segments of the target document and the comparison document, the values of inner products being calculated between the corresponding document segment vector and the topic difference factor vectors of the respective orders;
• (e) computing degrees of distinctiveness of said respective orders and a total degree of distinctiveness for each term contained in the target document, on the basis of correlation coefficients between frequencies of each term in the respective document segments and the values of the inner products;
• (f) identifying a distinctive combination of terms in the target document, on the basis of the degrees of distinctiveness of said respective orders or the total degree of distinctiveness thereof;
• and
• (g) transmitting an output to a device wherein the output comprises the identified distinctive combination of terms in the target document.

A method of evaluating a degree of distinctiveness of each combination of terms contained in a target document including at least one document segment with respect to a comparison document including at least one document segment, and identifying a distinctive combination of terms, the method comprising:

• (a) identifying a respective document segment vector for each document segment contained in the comparison document and the target document, each document segment having component values associated with occurring frequencies of terms occurring in the document segment;
• (b) from the document segment vectors, computing squared sum matrices respectively corresponding to the comparison document and the target document;
• (c) computing a predetermined number of orders of topic difference factor vectors of the target document from the squared sum matrices respectively corresponding to the comparison document and the target document;
• (d) computing values of inner products for each of said document segments of the target document and the comparison document, said values of inner products being calculated between the corresponding document segment vector and the topic difference factor vectors of the respective orders;
• (e) computing degrees of distinctiveness of said respective orders and a total degree of distinctiveness for each combination of terms contained in the target document, on the basis of correlation coefficients between frequencies of each combination of terms in the respective document segments and the values of the inner products;
• (f) identifying a distinctive combination of terms in the target document, on the basis of the degrees of distinctiveness of said respective orders or the total degree of distinctiveness thereof;
• and
• (g) transmitting an output to a device wherein the output comprises the identified distinctive combination of terms in the target document.