A key challenge to retrieval in any type of system is how to represent the resources appropriately so that the user(s) can fi nd what they are looking for. In systems being used by children, as well as those designed specifi cally for children, there exist two fundamental representation problems: (1) the metadata or representation scheme of the system may not be designed with this specifi c user group in mind, and (2) few age-appropriate controlled vocabularies exist for use in creating metadata. Existing research in these two problem areas and the impact on the users' information seeking and retrieval experiences are presented. Current projects and developments, and the contribution that the users themselves can provide, will give the reader further insight into the issues and potential opportunities for research and application.