Rhetorical Invocation: A Four-Layer Computational Analysis of Discourse Vocabulary in Institutional Art Writing

In fields where output quality cannot be assessed through objective metrics, institutional authority is produced partly through language. Institutions deploy specialised vocabulary to signal analytical sophistication and field membership. Whether this language performs the argumentative operations it formally resembles has not been measured at scale.This study develops a four-layer computational framework to quantify how institutional discourse vocabulary diverges structurally from academic writing. The framework is applied to approximately 62,400 texts from 13 major art institutions, compared against 1,673 peer-reviewed articles across eight discourse categories.Four independent metrics converge. First, institutional texts achieve syntactic convergence with academic writing when document length is controlled (adjusted *d* = -0.12), because they adopt the same post-nominal modification structures that characterise academic prose. Second, within individual documents, IAE-suffix adjectives form no repeated adjective-noun pairs (mean nMCE = 0.972; *d* = +2.00 vs. academic baseline). This pattern holds across all 13 institutions. Third, discourse keywords appear without explicit causal or contrastive connectives in 60.1% of institutional documents versus 20.0% in academic texts (OR = 5.48 [4.86, 6.18]). Fourth, two independent large language models assign Analytical Tendency scores 3.5 times below the academic baseline.Within the institutional corpus itself, lower modifier uniformity predicts higher analytical tendency by a factor of 7.1, a gradient that operates independently of domain-specific conventions. These findings define *rhetorical invocation*: the deployment of formal markers of analytical rigour in contexts structurally decoupled from the argumentative operations those markers support in academic writing. The measurement framework combines information-theoretic, dependency-syntactic, discourse-connective, and log-probability metrics. It requires no domain-specific assumptions and is transferable to any institutional corpus where language performs symbolic authority.Keywords: institutional discourse, computational discourse analysis, register analysis, International Art English, NLP, LLM evaluation, rhetorical invocation