FSTE (Functional, Socio-Cultural, Technological & Ethical-Sustainability) Framework: A Multi-Dimensional Instrument for Evaluating the Universality of Personal Accessories

Personal accessories are undergoing a profound transformation, driven by the integration of adaptive smart technology, that are expanding both their functional capabilities and symbolic significance. As artefacts, they are both utilitarian tools and material expressions of cultural identity. Among many existing frameworks, most of the contemporary universal design models address only singular dimensions like ergonomics, usability, or cultural symbolism. No existing validated multidimensional assessment framework fulfils the conditions of functional universality, socio-cultural inclusivity, technological accessibility, and ethical sustainability together. A systematic review of more than twenty published models of universal design (UD) confirms this lacuna and shows that existing frameworks are mainly unidimensional, Western-centric, and structurally inadequate for evaluating today's smart accessory ecosystems. This paper presents the FSTE (Functional, Socio-Cultural, Technological, Ethical-Sustainability) Framework as the first empirically validated (through expert and user pilot study) multidimensional evaluation instrument for assessing the universality of personal accessories. The framework was developed through expert Delphi validation (n = 15; α = 0.87; κ = 0.81) and a user pilot study (n = 15 users across three product categories); user pilot study confirmed discriminant validity across product types (D1 mean = 3.95; D2 = 3.53; D3 = 3.57; D4 = 3.77). The FSTE comprises four dimensions, nine parameters, and twenty-seven measurable indicators.