Answer:
Dinn's maze performance when assisted by a skilled helper
Explanation:
The zone of proximal development is defined as the distance that exist between the level of actual development obtained from independent problem solving the the potential development level, obtained from solving a problem under guidance by an adult or when collaborating with peers that are capable to solve the problem. Hence to determine the zone of proximal development, Dr Mc Coy must measure Jim’s personal performance on the maze and his maze performance when assisted by a skilled helper.