Composite Justification and the Organisational Legitimation of Data Science

Why do data scientists, despite their growing organisational importance, still have to justify their value? Drawing on interviews with data science professionals (DSPs) and related actors in Scotland, this article offers a micro-moral account of legitimacy work in an emerging technical occupation. DSPs are relied upon for technical expertise yet lack institutionalised authority and operate within organisations marked by conflicting evaluative expectations. The article argues that legitimacy is constructed not through professional closure or institutional recognition, but through the situated moral reasoning DSPs perform in everyday organisational life. Using Boltanski and Thévenot’s orders of worth framework, the analysis develops composite justification as the central mechanism: the active combination of evaluative principles DSPs use to render their work intelligible and valuable to varied organisational audiences. The article identifies three forms of justificatory vulnerability: dominance, where organisational power outweighs intelligible claims; incommensurability, where claims cannot be translated across evaluative orders; and infrastructural breakdown, where the material preconditions for justification are missing. Findings show that legitimacy for this occupation does not rest on jurisdictional closure but on the provisional moral composites DSPs assemble under organisational dependence, contributing a processual, micro-moral account to debates on evaluation, morality and the organisation of expert labour.