This study looked at 30 primary aged children between 10 and 11 years old who were visiting the Eden Project, Cornwall and participating in workshops led and designed by the Eden Education Officers. The study attempted to directly test the effects of the Education Officers' workshops on children's learning. Personal meaning mapping, a constructivist approach was used to measure change in the children's understanding along four semi-independent dimensions: extent, breadth, depth and mastery. The children's mastery of the subject regardless of ability was improved. Most of the workshop aims, such as "to recognise some plant adaptations in the humid tropics climate" were shown to have been met. The research also highlighted areas to be reviewed, such as educating children about the way indigenous people use plants for their survival and also how children can transfer knowledge, so that they can understand the significance of plants in their own daily lives. (Contains 2 tables and 2 figures.)