| A | Director of a kindergarten | 29 years | In 2006, Leading the study on the improvement of infants' language expression skills through natural experiencesIn 2008, obtained a master's degree in research on infant forests |
| B | Kindergarten teacher | 18 years | Participated in classes at the Seoul forest visitor centers for little childrenParticipation in the forest program run by kindergarten |
| C | Forest guide for little children | 13 years | In 2012, participated in monitoring infant observation at the Seoul infant forest experience centerIn 2014, participated in writing out the manual of forest experience center by the Korea forest service |
| D | Forest guide for little children | 8 years | Working as forest guide for little children in Seoul(Gwanak-gu) |
| E | Forest guide for little children | 8 years | Working as forest guide for little children in Seoul(Gwangjin-gu) |