It is virtually axiomatic that a more extended learning experience will have more impact than a one-off experience. But how much difference does it make and is the extended time commitment justified by the results? The Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust (BBOWT) conducted some research to explore this question with regard to the relative learning benefits of two different types of environmental education programmes in Caldecott Primary School in Abingdon, Oxfordshire, and William Harding School in Aylesbury, Buckinghamshire. The programmes in both primary schools began with an evaluation of 90 year 1 (ages 5-6) children's nature knowledge in a series of one-to-one interviews to set a baseline. The analysis of the interviews showed that the children in both schools learned a great deal about woodlice and other small organisms. BBOWT educators were not surprised to find that the William Harding children, who experienced a more extended programme, learned more than the Caldecott children. What did surprise them was the extent of that difference. Consideration of the programmes themselves suggests certain hypotheses about what may have contributed to the different results. Longer, deeper experiences give more opportunity to reinforce learning.