@harmon.ie/duplicate-text-detector

text-duplicates-detector

Detects duplication in text

In a nutshell

Our purpose is to be able to count the number of unique occurences of a phrase in a corpus. The challenge is to be able to define what we mean exactly by unique.

This module provides a set of functions that detects whether occurences of a phrase in some texts are duplicate. By duplicate, we mean similar texts up to irrelevant modifications.

For instance, if we look at two pieces of text:

After a long period of inactivity, an intersting opportunity for IBM occurred last week.

The last period was not exciting due to the negociations that lead nowhere, until an intersting opportunity for Google occurred last week.

In the neighborhood of period, the texts are not similar while in the neighborhood of opportunity, the texts are similar.

We say that the occurences of period are not duplicate while the occurrences of opportunity are duplicate.

Usage

Node

Install:

npm install @harmon.ie/duplicate-text-detector

or

yarn add @harmon.ie/duplicate-text-detector

const dup = require('@harmon.ie/duplicate-text-detector');

const text1 = `After a long period of inactivity, an intersting opportunity for IBM occurred last week.`;
const text2 = `The last period was not exciting due to the negociations that lead nowhere, until an intersting opportunity for Google occurred last week.`;

dup.isDuplicate(text1, text2, 'period'); // returns false
dup.isDuplicate(text1, text2, 'opportunity'); // returns true

Browser

TBD

API Reference

Limitations and known issues

Limitations

• Only the english language is supported.

Known issues

• Only the first instance of the phrase in the texts are taken into account.

How does it work ?

The library implements a simple algorithm to detect lines that are candidate for being the start of a signature, and score each candidate by examining the lines following the start.

Example of trigger candidates:

• name of the email sender
• words such as Thanks and Regards

The score of each candidate is determined by the likelihood of the following lines to be part of the signature. Each of the lines that follow a trigger candidiate is given a score that relates to this likelihood.

Example of lines with high score:

• phone number
• email address
• url
• sender name.

Also, we implement some heuristics, for instance:

• long lines should not appear too much in signature
• signatures should not have too many lines

Note: The detectors of phone numbers, email addresses and urls are simple and their purpose is to support the signature scoring. They shouldn't be used standalone. Please refer to a specialized detector and validation libraries for that.

Roadmap and Contributions