Courts focus on the Substantial Similarity test to determine copyright infringement. They also use testimony from experts and lay people. As a result, there is a tension between preserving artist’s rights and preserving a competitive market. This tension is especially problematic in the context of copyright protection of computer software. Nonetheless, copyright law does protect computer software. Resulting amendments in the Copyright Act defined "computer program" and ensured that copyright protection was extended to all computer programs. The Substantial Similarity test applied to computer programs creates several concerns. Lack of access to expert testimony in the crucial second phase of the test had proven unworkable in the context of computer programs. One leading commentator has stated that "the crucial flaw in [Whelan's] reasoning is that it assumes that only one "idea,' in copyright law terms, underlies any computer program, and that once a separable idea can be identified, everything else must be expression." However, no computer program can be said to be made up of one idea, at least on a functional level. Courts suggested another step: if it found substantial similarity, it would then determine if the defendant misappropriated a "substantial portion" of the copyrighted program. The Tenth Circuit addressed the Altai test and the use of expert testimony in computer copyright infringement actions. No one is better equipped to reverse engineer a computer program than a computer programmer.
Jeffrey D. Coulter, Computers, Copyright and Substantial Similarity: The Test Reconsidered, 14 J. Marshall J. Computer & Info. L. 47 (1995)