## Markers of Adulthood Subscale Development: Comparative Review and Assessment of Inductive and Deductive Psychometrics ## ---------- **Nathan E. Fosse**, [Harvard University][1] ---------- **Downloads** [Full Research Report][2] [Methodological Addendum][3] ---------- **Executive Summary** We describe two psychometric approaches undertaken to generate 8 subscales from the 40 Markers of Adulthood (MoA) items in the EAMMI survey. First, we describe the inductive approach, drawing from empirical analyses of 20 of the items. Second we describe the deductive approach toward scale construction. In addition to describing the processes of scale construction, we also describe the attributes and psychometric properties of the scales derived. Finally, we assess the inter-construct validity of inductive vis-a-vis deductive approaches, finding high correlations between the two sets of measures. In addition, we draw from use of the 40 MoA items in the extant literature to provide a comparative analyses of the EAMMI items. We find that, despite divergent 'styles' of psychometric reasoning, both approaches are consistent with the strengths and he challenges of constructing scales in the literature. We conclude with a review of the lessons learned. Included in he appendix are results of by the first author of a replication and extension of principal components analysis. **Keywords:** *Markers of Adulthood,* *deducive reasoning*, *psychometrics*, *Emerging Adulthood at Multiple Institutions (EAMMI)* ---------- **Methodological Addendum** Also available for download is a .pdf the syntax written by N. Fosse to generate mean scores, total scores, and scale reliabilities in he EAMMI data. The attached file is the output or the 'log file' produced when coding in Stata/SE. Analyses review Stata's version to be set to 13, but can be employed using Stata/IC. Readers should note the file is 131 pages long. Syntax relevanto the construction of the MoA items and he IDEA items are invited to start p. 17. The syntax file cleans, inspects, and lables each of the 71 emerging adulthood items. Then N. Fosse produces, with annotations, to generate the mean scores and their reliabilities of the MoA and IDEA mean scores in the EAMMI survey. [1]: https://www.linkedin.com/in/nathanfosse [2]: https://osf.io/qn4f6/ [3]: https://osf.io/vb3ex/