This week’s SundayArts Choice looks at a decade of experimental projects from the Young Architects Program. This competition, organized by the P.S.1 Contemporary Art Center and The Museum of Modern Art, asks young architects to design outdoor structures that provide an ingenious interplay of shade, water and robust seating — essential elements for the thousands of visitors who enjoy summer events at P.S. 1. In this segment guided by Barry Bergdoll, MoMA’s Chief Curator of Architecture and Design, check out afterparty, an outdoors installation created by MOS, which won the tenth annual MoMA/P.S.1 Young Architects Program competition, and the YAP 10th Anniversary Review, a special exhibition inside the museum.