Deregowski, J. B. & Jahoda, G. (1975). Efficacy of objects, pictures and words in a simple learning task. International Journal of Psychology, 10, 19-25.

Adult subjects were required to memorise positions associated with twelve common objects, their pictures and their names. Both written and spoken names were used. It was found that learning was gastest with the objects and slowest with verbal symbols, and that pictures occupied an intermediate position. The data suggest that the errors observed are partly due to differential forgetting of various types of stimuli and partly perhaps to differential difficulty in making deductions from them.