Methods and systems for annotating electronic documents

1. A computer-implemented method of annotating an electronic document comprising:

receiving annotation information corresponding to a first electronic document file, wherein the first electronic document file is a text document;

creating annotation metadata that is associated with the annotation information and comprises contextual information relating to an annotation location in the first electronic document file, wherein:

the annotation metadata is created by assigning a target offset value to individual neighboring tokens defining an annotation neighborhood, wherein the target offset values correspond to positions of the neighboring tokens with respect to the annotation location within the first electronic document file; and

the target offset value of each neighboring token provides a candidate anchoring position;

storing the annotation information and associated annotation metadata in an annotation file that is separate from the first electronic document file;

creating a first document signature of the first electronic document file;

creating a second document signature of a target electronic document file;

comparing the first document signature to the second document signature to generate a document similarity value; and

comparing the document similarity value to a threshold similarity value, wherein the first electronic document file and the target electronic document file are compatible documents when the document similarity value is greater than the threshold similarity value

anchoring, by a computer device, the annotation information to the target electronic document file at an anchor location corresponding to the annotation metadata, wherein the target electronic document file and the first electronic document file are compatible documents, and the target electronic document file is a modified version of the first electronic document file such that an underlying text of the target electronic document file is different from an underlying text of the first electronic document file, wherein anchoring the annotation information further comprises:

evaluating the candidate anchoring positions such that a weight of each candidate anchoring position is determined at least in part on an influence function;

selecting the candidate anchoring position having a maximum preference from the neighboring tokens as the anchor location; and

anchoring the annotation information at the anchor location within the target electronic document file.

2. The computer-implemented method of claim 1 , wherein:

the neighboring tokens comprise words within the first electronic document file; and

the target offset value of a particular neighboring token represents a number of words from which the particular neighboring token is separated from the annotation location.

3. The computer-implemented method of claim 1 , wherein neighboring tokens positioned in a first direction from the annotation location are assigned a positive target offset value and neighboring tokens positioned in a second direction from the annotation location are assigned a negative target offset value.

4. The computer-implemented method of claim 1 , wherein:

a base token is associated with the annotation location;

a magnitude of the target offset value of the base token is less than the magnitude of each of the remaining target offset values associated with the remaining neighborhood tokens; and

the magnitude of the target offset value of a neighboring token that is located relatively further from the annotation location is greater than the magnitude of the target offset value of a neighboring token that is located relatively closer to the annotation location.

5. The computer-implemented method of claim 1 , wherein:

the neighboring tokens comprise characters within the first electronic document; and

the target offset value of a particular neighboring token represents a number of characters from which the particular neighboring token is separated from the annotation location.

6. A computer-implemented method of annotating an electronic document comprising:

receiving annotation information corresponding to a first electronic document file, wherein the first electronic document file is a text document;

creating annotation metadata that is associated with the annotation information and comprises contextual information relating to an annotation location in the first electronic document file, wherein:

the annotation metadata is created by assigning a target offset value to individual neighboring tokens defining an annotation neighborhood, wherein the target offset values correspond to positions of the neighboring tokens with respect to the annotation location within the first electronic document file; and

the target offset value of each neighboring token provides a candidate anchoring position;

storing the annotation information and associated annotation metadata in an annotation file that is separate from the first electronic document file;

creating a first document signature of the first electronic document file;

creating a second document signature of a target electronic document file;

comparing the first document signature to the second document signature to generate a document similarity value; and

comparing the document similarity value to a threshold similarity value, wherein the first electronic document file and the target electronic document file are compatible documents when the document similarity value is greater than the threshold similarity value

anchoring, by a computer device, the annotation information to the target electronic document file at an anchor location corresponding to the annotation metadata, wherein the target electronic document file and the first electronic document file are compatible documents, and the target electronic document file is a modified version of the first electronic document file such that an underlying text of the target electronic document file is different from an underlying text of the first electronic document file, wherein anchoring the annotation information further comprises:

evaluating the candidate anchoring positions such that candidate anchoring positions of neighboring tokens positioned relatively distant from the annotation location are weighted less than candidate anchoring positions of neighboring tokens positioned relatively close to the annotation location in evaluating the candidate anchoring positions to select the anchor location;

selecting the candidate anchoring position having a maximum preference from the neighboring tokens as the anchor location; and

anchoring the annotation information at the anchor location within the target electronic document file.

7. The computer-implemented method of claim 6 , wherein:

the neighboring tokens comprise words within the first electronic document file; and

the target offset value of a particular neighboring token represents a number of words from which the particular neighboring token is separated from the annotation location.

8. The computer-implemented method of claim 6 , wherein neighboring tokens positioned in a first direction from the annotation location are assigned a positive target offset value and neighboring tokens positioned in a second direction from the annotation location are assigned a negative target offset value.

9. The computer-implemented method of claim 6 , wherein:

a base token is associated with the annotation location;

a magnitude of the target offset value of the base token is less than the magnitude of each of the remaining target offset values associated with the remaining neighborhood tokens; and

the magnitude of the target offset value of a neighboring token that is located relatively further from the annotation location is greater than the magnitude of the target offset value of a neighboring token that is located relatively closer to the annotation location.

10. The computer-implemented method of claim 6 , wherein:

the neighboring tokens comprise characters within the first electronic document; and

the target offset value of a particular neighboring token represents a number of characters from which the particular neighboring token is separated from the annotation location.