Socrative and Kahoot are student response systems used for formative assessment. While both are free, they each have strengths and weaknesses. Socrative allows for quick impromptu questions, different question types including short answer, and provides individual reports. However, students can't review questions after class. Kahoot has a game-like interface that motivates students, but lacks question and individual reports. After reviewing features, the document recommends Socrative for its enhanced student interaction and participation capabilities.