The use of Interactive Evolutionary Computation (IEC) is suitable to the development of art-creation aid system for beginners. This is because of important features of IEC, like the ability of optimizing with ambiguous evaluation measures, and not requiring special knowledge about art-creation. With the popularity of Consumer Generated Media, many beginners in term of art-creation are interested in creating their own original art works. Thus developing of useful IEC system for musical creation is an urgent task. However, user-assist functions for IEC proposed in pastworks decrease the possibility of getting good unexpected results, which is an important feature of art-creation with IEC. In this paper, The author proposes a new IEC evaluation process named "Shopping Basket" procedure IEC. In the procedure, an user-assist function called Similarity-Based Reasoning allows for natural evaluation by the user. The function reduces user’s burden without reducing the possibility of unexpected results. The author performs an experiment where subjects use the new interface to validate it. As a result of the experiment, the author concludes that the new interface is better to motivate users to compose with IEC system than the old interface.