Utilizing the Rabin-Karp Algorithm in Plagiarism Detection

Consider you're a professor at a large university who has just given your students an assignment. As you begin checking the hundreds of submissions, you find a number of them strikingly similar. This scenario, a common predicament in academia, is where the Rabin-Karp Algorithm can be an effective tool. This algorithm, known for its pattern searching capabilities, can be utilized to detect potential cases of plagiarism.

Understanding the Rabin-Karp Algorithm

• Pattern Hashing: The Rabin-Karp algorithm hashes the pattern (text piece) we're looking for and then hashes all sequences in the text of the same length.
• Comparisons: By comparing hash values, the algorithm identifies potential matches much quickly than comparing strings directly. It does this by moving a sliding window across the text.
• Hash Function: The function used in Rabin-Karp is called a rolling hash, which recalculates the hash value efficiently when the window moves.
• Confirmation of Match: In case of a hash match, the algorithm double-checks character by character to confirm a match, which takes care of false positives.

Practical Application: Detecting Plagiarism

Step 1: Hash the source documents

• Task: Hash sequences of text in the documents you are comparing against for plagiarism.
• Focus: You should choose a suitable length for the text sequences.

Step 2: Hash the student's papers

• Task: Slide a window of the same length across the students' submissions, generating hash values for each sequence.
• Focus: Pay attention to hash values that match those in the source documents.

Step 3: Confirm cases of plagiarism

• Task: When a hash match is found, confirm it by double-checking the text sequences character by character.
• Focus: Identify which parts of the text are directly copied from the source material without proper citation.

Benefits of Using Rabin-Karp

The Rabin-Karp algorithm offers a fast and efficient solution to detect potential plagiarism, even in large sets of documents. It speeds up the plagiarism detection process by quickly identifying potential matches through hash comparisons. Its rolling hash function enables fast computation when the window moves across the text.

By using the Rabin-Karp algorithm in a plagiarism detection tool, you, as a professor or an academic institution, can effectively uphold the integrity of academics and curb unethical practices. It ensures fair assessment of students' work and encourages authentic research.