Think about the design that worked the best. Could you improve the best design and raise its internal temperature? Think about what materials you could use to improve the design. Here are some things to consider: How does the size of the reflective surface affect the temperature of the oven? Would insulating the oven help it retain heat, or would more heat be lost? Would a tighter or a looser cover heat the oven faster? How about no covering at all? Describe how you plan to improve the efficiency of the best oven design.