The evidence - eudaimonic measures
Most eudaimonic measures do not tend to specify a reference period for respondents. For example, neither the eudaimonia nor flourishing scale created from items in the European Social Survey (Huppert et al., 2009; Huppert and So, 2011; Clark and Senik, 2011) nor the Psychological Well-Being Scale proposed by Diener and Biswas-Diener (2009) provide specific guidance to respondents about the reference period in question. The European Social Survey refers to what respondents generally or always feel, whereas the Psychological Well-Being Scale asks respondents the extent to which they agree or disagree with a series of statements about their lives (e.g. I lead a purposeful and meaningful life) - further examples are available at Annex A. Respondents are thus presumably expected to indicate their views at the present moment, but looking back across their lives for an undefined period. As with evaluative measures, it is not yet clear to what extent responses might be altered by different reference periods. As a consequence, it will be important to maintain a consistency of approach until further evidence is available.