Abstract

Introduction: The act of plagiarism is represented by using someone else’s information or research without the author’s consent and/or without the author’s full acknowledgement. Detection of plagiarism can be easily made using computer software that identifies fragments of texts as not original. Aim: This study aimed to highlight and compare the performance in detecting a specific type of plagiarism (copy-paste) in different types of documents between free and commercial software. Material and Method: A document of 808 words was created using eight fragments of texts from eight different sources. Two other versions of the document were then created: one with approximately 43% of the text similar and another with the entire text paraphrased. Seven software programs were used for the similarity analysis of each of the three texts (4 commercial and 3 free). Results: The original document showed differences in detection performances (Turnitin – 97% observed similarity, and Plagiarism detector – 93% observed similarity, had the highest performance). In the document with 43% similarity, the performance was affected across all programs, but Plagiarism detector had the best performance (43% observed similarity). None of the evaluated software could detect the original sources in the entire paraphrased document. Conclusion: Among the tested software, Turnitin proved to be the best commercial software and Plagiarism detector the best free software for testing academic documents similarity, differences between them being minimal.

Keywords

Plagiarism, Similarity, Performance, Software