Towards addressing ontological issues in design cognition research. this paper presents the first generic classification of cognitive processes investigated in protocol studies on conceptual design cognition. The classification is based on a systematic review of 47 studies published over the past 30 years. Three viewpoints on the nature of design cognition are outlined (search. https://www.roneverhart.com/HP-Pavilion-15-eg2373cl-15-6-FHD-Touch-Laptop-Intel-Core-i7-1255U-3-50-GHz-GeForce-MX550-16GB-DDR4-512GB-SSD-Windows--p8309/