Web-based collective design platforms are virtual environments which highly rely on large-scale participation of people from diverse backgrounds in different phases of the design process. Understanding and motivating participants is important to enhance the diversity of solutions and approaches in such platforms. This study investigates the motivation factors for the designer members of the crowd, and explores the perceived values of these platforms from the perspective of industrial designers. An empirical study based on semi-structured interviews with novice industrial designers was conducted in reference to two collective design platforms, Quirky and OpenIDEO. The study reveals six major values emphasized by the designers: Supportiveness, collectiveness, appreciativeness, responsiveness, trustworthiness, and tangibility of outcome. The findings indicate that the value of collectiveness may be interrelated with the values of supportiveness, appreciativeness and responsiveness. Trustworthiness is a complex construct; participation quality, evaluation quality, reward system, intellectual property and past performance are the related issues brought to focus by designers. The tangibility of outcome may provide a useful reference for re-interpreting the perceived values in accordance with the type of the collective platform.