Table 1 Criteria related to primary research question and selecting a theoretical framework and corresponding methods

Reflection on the relationship between empirical and ethical–normative/ethical–descriptive research questions (even if the ethical motivation is more prominent than the ethical research question)

• Can an explicit distinction be made between the empirical and ethical research questions? (e.g. a distinction between interviewing patients about their wishes and the ethical weight given to patient autonomy) [22, 23]

• How dependent is the empirical research question on particular ethical background assumptions? (e.g. justification for the selection of a target group for a questionnaire: why do we think their opinion is ethically relevant?) [70]

• How is the ethical research question dependent on empirical or socio-theoretical background assumptions? (e.g. ethical considerations of vulnerability of a particular group such as pregnant women: what are the underlying anthropological or psychological considerations? Are there any hidden gender-related stereotypes?) [66]

• What are the explicit and implicit research interests and motivations of the EE researchers? (e.g. is research with dying patients motivated by curiosity or the moral attempt to empower them? Is the researcher motivated to identify possible conflicts of interest or might the research serve mainly to produce more social acceptance of a technology?) [14, 69]

• What kind of epistemic research interest motivates the researcher to combine ethical and empirical research? (e.g. explaining whether the aim is the evaluation of established ethical practice, or of measures taken to improve ethical practice; or whether the aim is ethical theory-building, norm-construction, or legitimization/critique or a particular practice) [15]

Development/use of theoretical frameworks:

• How can a theoretical framework be developed; what are the main limitations of the chosen theoretical framework? (e.g. premises and limitations of a principle of autonomy, when analysing macro-social interactions) [22], see contributions in [67]

• Were potential ambiguities of central concepts considered within the theoretical framework? (e.g. to which extent is the concept of ‘identity’ used differently in current philosophy and in sociology when wanting to analyse the discourse of identity changes by neuroenhancement empirically and its ethical implications) [71, 72]

• How does the chosen medico-theoretical framework (e.g. concept of disease/health) fit into the ethical-normative framework? (e.g. does a science-positivistic concept of disease fit into a Kantian or hermeneutic approach of ethics?) [73]

• How does the chosen sociological-, cultural- or philosophical framework (e.g. concept of personal identity) fit into an ethical normative framework (e.g. approach to a cosmopolitical ethics of justice?) [74]

Use of empirical and ethical methods and their relationship to the theoretical framework:

• Are the chosen empirical methods compatible with the combined theoretical framework? (e.g. are interviews with doctors as experts compatible with a liberal, autonomy-driven approach that claims to empower patients?)

• What is the advantage of the chosen method in comparison to other available methods? (e.g. why and when to choose a deductive approach in applied ethics to assess ethical problems of a new technology and not an inductive, or hermeneutic one?) [66, 68]

• Are the chosen methodological approaches appropriate for the envisaged combined research question? (e.g. does the empirical method of interviewing parents generate results relevant for the ethical question of whether parents should be allowed to influence the genetic make-up of their children?)