Universität Bielefeld

© Simon A. Eugster

Research Design

History and Conceptualization

Our research designs for the study of individual religiosity and spirituality include a clear focus on religious development. For qualitative, biographical-reconstructive research, we opt for the Faith Development Interview that was created by James Fowler. As quantitative measure for religious development we developed the Religious Schema Scale (RSS).

In line with this strategy of combining qualitative and quantitative approaches the research designs of the major projects at the Research Center for Biographical Studies in Contemporary Religion are characterized by the triangulation of quantitative and qualitative approaches and by the combination of mixed methods. We think that with these instruments and their combination we make a contribution to the scientific study of religion – in which a polarization (and in part even opposition) between proponents of quantitative and qualitative research designs still exists.



We invite to participate in our survey consisting of psychometric scales (et al. well-being, personality, mystic experiences) and select among those, a number of participants for an interview; then we relate qualitative and quantitative data by including results of our interview evaluation into our quantitative data set, in order to integrate the information into our statistical analyses, and, on the other hand, for our case studies, we use case specific answers of the survey’s questionnaire.

Second, we mostly work within a comparative cultural perspective comparing Germany and the USA. Beginning with the Deconversion Study, continuing in the Spirituality Study, and in the current project with focus on religious styles development, all designs engage in a comparison between Germany and the USA. A third hallmark of our approach is the longitudinal perspective. The Faith Development Interview (FDI) invites autobiographical reconstructions, thereby introducing a diachronic perspective. With the research design of the current project we with a take the exploration of development one step further by including consecutive points of interviewing and questionnaire administration. Thus, we can trace change over time in psychometric measures as well as in subjective reconstructions of faith development and religious styles. Building on past research we have re-interviewed participants of the Deconversion Study and the Spirituality Project, while sampling for additional participants which we will also follow (see Current Research).

Development of Designs of Major Studies - Overview

Study / Design


Cultural Comparison

Longitudinal Design


Deconversion Narrative Interview, FDI, Psychometric measures

Germany - U.S.A.


FDI, Psychometric measures, Semantic Differentials, open entries for explorations of central concepts, IAT

Germany - U.S.A.

Longitudinal Study of Religious Development in Germany and U.S.A.

FDI, Psychometric measures

Germany - USA

FDI, Psychometric measures