This study studied the types of peer scaffolding presented in scientific experimental activities. The study included 14 university students. For the experimental activity of 'determining temperature changes using the meridian altitude of the sun,' information regarding experimental behaviors, thinking aloud, discourse, and retrospective interview data were collected and analyzed. A model was derived and utilized for experimental activities to analyze peer scaffolding, wherein students internally structured their experiences with the experimental activities. The results indicated that students utilized seven means of peer scaffolding: 'demonstrating', 'assisting', 'monitoring', 'posing', 'questioning', 'explaining', and 'suggesting'. Three types of peer scaffolding emerged: task completion-, model elaboration-, and learning support-oriented scaffolding. Each type differed in purpose, main mean, and major explanation details. Additionally, this study has observed the level of the model for the experimental activities and the time that had been provided to understand the experimental procedure influenced the three peer scaffolding types. These outcomes indicate that providing ample time to students independently structure the experimental procedure and supporting other students during experimental activities are essential. Moreover, providing assistance to students in focusing on observable phenomena by reducing the cognitive load required to process the experimental procedure is crucial.