Document Type : Research Paper


1 Associate Professor, Public International Law, Allameh Tabataba'i University, Tehran, Iran

2 Ph.D Student, Private Law, Allameh Tabataba’i University, Tehran, Iran


Legal systems have taken different approaches to Copyright infringement but the ultimate purpose of them is to prevent the intentional and unjust appropriation of the rights of the creators. The proof of copyright infringement is easy when some rights such as reproduction is infringed or literal appropriation has taken place. However, it would be difficult to prove infringement when the plaintiff claims that defendant appropriated a material amount of his original work with some differences. The main question is how much similarities are too much? there is no definitive standard in the law, but courts believe that infringement occurs when the defendant’s work bears a substantial similarity to plaintiff's work and to achieve that they have introduced various tests. This article seeks to explain the concept of substantial similarity in Copyright infringement and the way to achieve it. The result of the research is the choice of one or more tests from the four available tests depending on the type and nature of the work. However, in all choices, it is necessary to separate protected from unprotected elements and dichotomy between idea and expression in the work. This article also show that qualitative similarities are more important than quantitative similarities.


  • کتاب

    • کلمبه، کلود، اصول بنیادین حقوق مؤلف و حقوق مجاور در جهان، ترجمه علی‌رضا محمدزاده وادقانی (تهران: نشر میزان، 1385).


    • انصاری، باقر، «شرایط اثر قابل حمایت در نظام مالکیت ادبی و هنری (کپی‌رایت)»، مجله تحقیقات حقوقی، شماره 45، (1386).
    • زاهدی، مهدی، شریف‌زاده، شیرین، «آثار گردآوری شده و اصالت»، پژوهش حقوق عمومی، سال بیستم، شماره 60، (1397).
    • زرکلام، ستار، «تبیین مفهوم اصالت در حقوق مالکیت ادبی و هنری»، پژوهش حقوق و سیاست، شماره 22، (1386).
    • شاکری، زهرا، «استفاده منصفانه از آثار ادبی و هنری؟! حتی برای جامعه»، فصلنامه مطالعات حقوق خصوصی، شماره 2، (1394).
    • محمدی، پژمان، «نقد یک رأی در مورد مالکیت ادبی و هنری مفهوم و معیارهای اثر و نقض حقوق مالی آن»، فصلنامه مطالعات حقوق خصوصی، دوره 42، شماره 2، (1391).



    • Balganesh, Shyamkrishna, “The Normativety of Copying in Copyright Law”, Duke Law Journal, Vol. 62: 2, (2012).
    • Balganesh, Shyamkrishna, Manta Irina D, Ryan, Wilkkinson Tess, “Judging Similarity”, Iowa Law Review, Vol. 100, 14, (2014).
    • Chandrachud, Abhinav, “The Idea/Expression Fallacy: Effecting the Traditional and Doctrinaire Limits”, The Law Review, Government Law College, Vol. 4, (2005).
    • Cohen, Amy B, “Masking Copyright Decision Making: The Meaninglessness of Substantial Similarity”, University of California, Vol. 20, 719, (1987).
    • Dalmau, Gabriel Godoy, “Substantial Similarity: Kohus Got it Right”, Michigan Business & Entrepreneurial Law Review, Vol. 6, 2, (2017).
    • Fromer, Jeanne C, “An Information Theory of Copyright Law”, Emory Law Journal, Vol. 64, 71, (2014).
    • Helfing, Robert F, “Substantially Similarity in Literary Infringement Case: A Chart for Turbid Waterrs”, UCLA Entertainment Law Review, Vol. 21, 1, (2014).
    • Hickey, Kevin J, “Reforming Similarity Analysis in Copyright”, Washington University Law Review, Vol. 93, 681, (2016).
    • Jones, Richard H, “The Myth of Idea/Expression Dichotomy in Copyright Law”, Pace Law Review, Vol. 10, 551, (1990).
    • Lee, Moon Hee, “Seeing’s Insight: Toward a Visual Substantial Similarity Test for Copyright Infringement of Pictorial, Graphic and Sculptural Works”, Northwestern University Law Review, Vol. 111, 3, (2017).
    • McDonagh, Luck, “Is the Creative Use of Musical Works without a Licence Acceptable under Copyright Law?”, International Review of Intellectual Property and Competition Law, Vol. 43, 4, (2012).
    • Parelman, Bruce, “Proving Copyright Infringement of Computer Software: An Analytical Framework”, Loyola of Los Angeles Law Review, Vol. 18, (1985).
    • Poston, Karen L, “All Puff and No Stuff: Avoiding the Idea/Expression Dichotomy”, Loyola Entertainment Law Journal, Vol. 9, No. 2, )1989(.
    • Ros, Vioral, Livadariu, Andrea, “Originality-Condition for Protection of Scientific works”, Nicolae Titulescu University House Romania, Vol. 4, 1, (2014).
    • Sprigman, Christopher Jon, Hedrick, Samantha Fink, “The Filtration Problem in Copyright’s Substantially Similarity Test”, Lewis & Clark Law Review, Vol. 23, 3, (2019).
    • Wilde, Edward C, “Replacing the Idea/Expression Metaphor with a Market-Based Analysis in Copyright Infringement Actions”, Whittier Law Review, Vol. 16, 3, (1995).
    • Versteeg, Russ, “Rethinking Originality”, William & Mary Law Review, Vol. 34, (1993).
    • Yen, Alfred C, “A First Amendment Perspective on the Idea/Expression Dichotomy and Copyright in a Work’s Total Concept and Feel”, Ohio State Law Journal, Vol. 1, 517, (1990).


    • Arnstein v.Porter 154 F.2d 464 (1946).
    • Daly v. Plamer 36 How. Pr.206 (1868).
    • Dawson v. Hinshow Music Inc, 905 F.2d 731 (1990).
    • Feist Publication, Inc v. Rural Telephone Service Co, 499 U.S 340,111 S.Ct 1282 (1991).
    • Harper & Row, Publishers Inc v. Nation Enterprises, 471 U.S (1985).
    • Knitwaves, Inc v. Lollytogo Ltd, 104 F3d 353 (1996).
    • Narayan Rao v. v Prasad 2 APLJ (1979).
    • North Coast Industries v. Jason Maxwell, Inc, 972 F.2d 1031 (1992).
    • Novelty Textile Mills v. Joan Fabrics Crop 558 F.2d 1090 (1977).
    • Roth Greeting Cards v. United Card Co, 429 F.2d 1106 (1970).
    • Samuel S. Green v. William Bishop.
    • Sid & Marty Krofft Television prod, Inc v. Mcdonald’s Crop, 562 F.2d 1157 (1977).
    • Warner Bros v. American Broadcasting Company Inc, 720 F.2d 231 (1983).