With the expansion of the user-oriented approach, the attention to the exclusive orientation on the functionality of the system itself has no longer been paid. Users with specific information needs and user requirements, to which system developers were forced to respond, became more and more important. In addition, the diffusion of information and communication technologies into the individual's daily life has led to the consideration of diverse user groups, including children, whose limited information and digital competences oft en prevent the effective use of information systems aimed primarily at the adult user. Therefore, the concept of user experience and participatory design, based on the real needs and requirements of potential users, comes to the fore among experts dealing with the usability of web interfaces of Online Public Access Catalogue (OPAC) systems. The paper deals with previous findings in the field of the information behaviour of children while interacting with online library catalogues and with the consideration degree of the resulting criteria in designing OPAC systems used in Slovakia. It also maps previous efforts to apply participatory design linking the requirements and expectations of child users with the design and functioning of library information systems, while evaluating the potential of participatory design in relation to the issue. [ABSTRACT FROM AUTHOR]