Technological products such as mobile phones have the potential to increase the quality of life among older people through enhancing communication networks and recreation. However, surveys have shown that older populations are slower to adopt new technological products compared with younger populations. Due to technological advances, the way we interact with information and communication technology (ICT) products has changed significantly in the past century and this affects a person's attitude and behaviour towards these products. This paper proposes a new approach for designing technological products, which in addition to considering age-related decline in ability, takes into account both the formative age when the use of technologies is first learnt, and the 'technology era' in which this occurred, e.g. whether this was the era of analogue or digital products. Using a multi-method approach (i.e. using different methods on the same object of study) through interviews and quantified by the performances of users of different ages and cohorts using past and current ICT products, a technology generation effect (TGE) was confirmed. The author proposes that in the interaction design of new ICT products, and in order for these to be acceptable and used effectively by older people, it is essential to consider users' own historical frames of reference and mental models of interaction. The visual Generation Timeline Tool (GTT), which was developed to facilitate this research, was evaluated by student designers. One of the outcomes was that the GTT was able to assist designers in taking TGE into account when designing new products. The paper also discusses the implications of this research on product development.