Plagiarism Detection System using Python with Text Similarity Analysis and Result Visualization

To provide an effective plagiarism detection mechanism in the ever-growing amount of digital content in academia, research, and business environments, a highly developed need exists for reliable plagiarism detection mechanisms. An integrated plagiarism detection technique combining natural language processing (NLP) methodologies with statistical similarity metrics to detect similar content within many different documents utilizing a python based platform is presented herein. All input documents are first pre-processed by means of tokenizing the input texts and removing stop-words to obtain a reduced set of only meaningful tokens. Each document is then transformed into a numeric vector using the TF-IDF methodology which emphasizes uniquely occurring terms within each document and diminishes commonality among words in the other documents. Pairwise cosine similarity is then computed for all combinations of documents resulting in a similarity matrix where each entry represents the degree of similarity between the corresponding pair of documents. Five documents representing three disciplines were utilized to test this technique. High similarity scores were reported (0.7) between documents one and two which represent the same content regarding machine learning, indicating that they represented plagiarism cases. In contrast low-similarity scores were reported for unrelated document pairs, greatly reducing false positives. Moderate similarities (0.55) were also reported for two related climate science documents; these values indicate some degree of overlap but no direct plagiarism