A case study and a cross-sectional experiment was carried out to investigate which aspects of current user interface complexity caused difficulties with users of different age groups and in what ways the handling of user interface affected the performance with respect to age and experience.  Concurrently, throughout the research, a conceptual visual tool – the Generation Timeline Tool (GTT) was developed.

The main method for data collection for the case study was research interview, in conjunction with the GTT.   It was found that older participants aged 46 or older had more statements concerning procedural difficulties, which involves interface with menus, than younger participants.  Lack of experience with such multi-layered interfaces was mentioned among older participants.

A cross-sectional study was conducted to investigate the relationship between age groups and multi-layered interfaces.  It was found that in task duration performance, there was an age effect.  In successful completion rate, the 56-65 and 66- and above age groups have a lower rate of success on products with two or three layers of interface indicating a generation effect, suggesting that older participants have generation-related lack of experience with current user interface.

The GTT, although designed to be a research tool to assist the researcher has indicated that it may be able to provide other designers with guidance in understanding the generation-related experience and make appropriate changes to their design to make their products more inclusive.  Design students evaluated the GTT and feedback from the participants indicated that the GTT was useful in bringing about awareness and provoking consideration of technological, social and demographics trends in their target market and in the features of products that are required to meet the requirements of the end users effectively.