4. Methods
4.1. Theoretical framework development
To illustrate the challenges of achieving objective validity within participatory scenario planning processes, we use The Theory of Communicative Action (Habermas, 1984a,b) to reflect on a particular case study of scenario planning in a socio-technical context. Our post-hoc reflection of the scenario planning exercise was guided by indices drawn from our reading of Habermas' original text through which we identified relevant factors associated with the ‘ideal speech situation’. Care was taken to respect the principle of transcendental pragmatics whereby our indices would be generalizable. These factors are presented (in Table 1) as a set of criteria or indices that we used to interpret obstacles to ideal speech which appeared to be present in our scenario planning exercise and indeed in other scenario planning experiences that the authors have participated in. We proceeded by systematically evaluating individual elements or activities that comprised the case study scenario planning exercise against the indices. These activities are chronologically arranged in a matrix (Table 2) and a brief comment is given about the approximation to an ideal speech situation (as assessed by the researchers) that was achieved, according to the most relevant indices (see Table 1). Section 5 presents a more detailed account of some key findings in relation to scenario planning as Communicative Action arranged according to Habermas' triad; process, procedure and product (see Section 5.1).