The Human-Centred Design approach is based on the use of techniques that communicate, interact, empathise and stimulate the people involved, gaining a deep understanding of their needs, desires and experience that often transcend what people themselves achieve. The methods (Giacomin, 2014; Maguire, 2001) have been developed to improve product design by understanding and/or predicting human-product interaction (Stanton, 2014). For example, the development of contextual design techniques (Holtzblatt et al., 2004) has facilitated the analysis, classification and description of human-environment interactions. The increasing use of scenarios and personas has provided a basis for the description of people and contexts (Carroll, 2000) . The focus on emotional engagement during design (Chapman, 2005 ; Norman, 2005 ) has caused HCD methodologies to move definitively away from the initial engineering approach.
The methodologies available to designers today increase and develop considerably, sometimes borrowing methods from other fields, such as psychology or sociology. An example are the Cards of IDEO (2003) or LUMA (LUMA Institute, 2012) or the texts of Norman (2005) or Jordan (2000) . The methods can be classified according to their purpose or intended use: some allow the collection of information on people (anthropometric, cognitive, emotional, sociological or psychological data); others consist of techniques to interact with people in order to facilitate the exploration of meanings, desires, needs with both verbal and non-verbal techniques (an example are ethnographic interviews or focus groups); others concern the analysis of those mental processes that are not always directly accessible (e.g. body language analysis, direct observation or analysis of facial expressions); finally, many methods are based on reflection and discussion to simulate intuitions, opportunities and possible future scenarios (e.g. co-design or use of working prototypes).