In-Situ Adaptive Interfaces for Online Browsing: Design Dimensions for Intent-Responsive Automation and User Control

Online browsing often requires balancing open-ended exploration with focused comparison, yet most interfaces remain static regardless of user focus. Adaptive interfaces offer a way to better align interface presentation with browsing needs, but how such adaptations should be triggered, designed, and controlled in practice remains unclear. We investigate adaptive browsing interfaces that modify information hierarchy, information granularity, and session-based ordering in response to inferred browsing intent. Drawing from a conceptual framework of five adaptation dimensions, we implement ReLay, a browser-based probe that applies lightweight, in-situ adaptations automatically while allowing user overrides. In a two-phase study (n = 10), participants welcomed adaptive changes when they were transparent, consistent, and easily reversible. Users approached control as calibration rather than error correction, verifying system behavior before relying on it. These findings illustrate how intent-responsive, controllable adaptation can support browsing without diminishing user agency. Our work contributes (1) a conceptual framework for adaptive interface behaviors in online browsing, (2) an instantiation of the framework through three selected dimensions, and (3) empirical insights into user acceptance, control, and design implications for adaptive browsing systems.