“…The most easily measured, universally applicable aspect of play is the duration of play episodes, but this is very variable within both age-groups and individual children, depending on such factors as the type of play material being used, the social setting, and the frequency of distractions (cf. Bott, 1928;Herring and Koch, 1930;Gutteridge, 1935;Moyer and Gilmer, 1955;Lunzer, 1958). Barker etal.…”