Alternative explanation: backward counting displaces or interferes with the trigram; the decline need not show passive short-term decay across the delay.
Assess whether Peterson and Peterson's result supports short-term decay more strongly than the interference explanation described.
39 exam-style questions on Edexcel GCSE Psychology 2.2 Studies, covering 2.2.1 Bartlett (1932) War of the Ghosts and 2.2.2 Peterson and Peterson (1959). Each one has a worked solution and a mark scheme showing where the marks go.