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CHI '26 · Honorable mention · full-paper review · confidence medium-high

ENtry, Occupancy, EXit (NOX): A Model of Human-Robot Territorial Dynamics

Robin Bretin , Robin Dheilly , Jessica R. Cauchard

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NOX is a credible CHI contribution because it reframes robot-space interaction around territoriality rather than mere distance, and it backs that reframing with a reasonably sized vignette study. The main value is conceptual: a vocabulary and stage model that can organize future HRI work, while the empirical evidence shows the proposed friction points matter in a realistic domestic scenario.

Axes Lens

Rare contribution shape, typical evidence profile. The point here is not a score. It is to show what kind of claim the paper makes, and whether the evidence pattern is unusual or baseline in this 268 -review set.

Review Summary

This paper’s strongest contribution is not a new robot capability but a reframing of the problem space. Instead of treating spatial conflict as only a proxemics or navigation issue, it argues that people interpret robot presence through territorial norms: who may enter, occupy, and exit a space, and under what expectations. That is a meaningful departure from the common-sense HRI framing of space as a neutral physical backdrop. The NOX model packages that idea into a stage-based structure, which is useful because it gives researchers and designers a shared vocabulary for describing where territorial friction occurs. The validation evidence is appropriate for the claim level: a between-subjects vignette study with N = 290 is enough to test whether the proposed friction points map onto perceived affective and evaluative responses, and the paper reports exactly that kind of alignment. The results are not subtle: targeted friction points reliably reduce congruence and appropriateness and increase negative affect and defensive intent. At the same time, the evidence is still scenario-based, so the paper supports perceived appropriateness and defensive intent more directly than it supports real-world behavioral dynamics in deployed systems. The authors are also careful to note that the friction-point set is an initial reference framework rather than an exhaustive taxonomy, which is an important limitation because it keeps the model from being overread as complete. Likewise, the study is bounded by a domestic primary-territory bedroom scenario and a largely Western/North American participant pool, so the model’s content may shift across cultures, robot morphologies, and multi-stakeholder settings even if the underlying mechanism remains stable. In CHI terms, that makes the contribution solid and conceptually interesting, but not yet a field-validated theory of robot territoriality. The paper is therefore best read as a framework and empirical first step: it opens a neglected lens, names the stages, and shows that mismatches at those stages matter to users. Its broader impact will depend on whether later work can test the model across contexts, cultures, and live deployments, and whether the initial friction-point taxonomy can be refined without losing the clarity that makes NOX useful now.

What Changed

Canon before

Prior HRI work has emphasized proxemics and physical spacing, but this paper argues that territoriality—space as a social construct governing access, expectations, and behavior—has been under-modeled in HRI.

Departure from common sense

The paper argues that HRI should not treat space mainly as a physical backdrop or proxemic distance problem; instead, it should model territoriality as a social construct through which people regulate access and behavior. That reframing is the core conceptual departure.

Actual novelty

NOX is presented as a stage-based model of human–robot territorial dynamics organized around ENtry, Occupancy, and EXit, with friction points used to identify where robot behavior can violate territorial expectations. The novelty is a structured conceptual model plus a vocabulary for empirical work in this underexplored area.

Evidence

The paper develops NOX as a stage-based territorial model and validates it with a vignette-based between-subjects study (N = 290) in a domestic primary-territory setting. The results show targeted incongruence at friction points, with lower congruence, more negative affect, higher defensive intent, and lower appropriateness. The authors also explicitly note that the model is not exhaustive and that the study is bounded by a vignette-based, domestic, primary-territory design.

Limits

Method limits

The validation is based on vignette judgments rather than live interaction, so the evidence supports perceived territorial responses more directly than observed behavior in deployed systems. The authors also describe the friction-point set as an initial reference framework rather than an exhaustive taxonomy.

Deployment limits

The paper’s own framing suggests the model is most directly applicable to domestic primary territories and to robots whose presence is interpreted through access, occupancy, and exit norms. Transfer to other robot morphologies, cultures, or multi-stakeholder settings may require calibration and extension.

Boundary conditions

The claims are bounded by a vignette-based validation in a high-salience bedroom scenario with mostly North American participants. The model is strongest where users interpret robot behavior as territorial access regulation, space use, or authority negotiation, and weaker where those norms are absent or differently structured.

Manual check: false

Position in field

This positions the paper as a conceptual bridge from proxemics toward territoriality in HRI, offering a shared vocabulary and stage-based lens for studying spatial tensions in robot deployments. It is best read as an intermediate-level theory contribution with an empirical first validation, not as a fully general theory of all robot-space interaction.

Abstract

Spatial tensions in real-world deployments of autonomous robots (e.g., sidewalk conflicts, boundary violations) expose a critical oversight: the neglect of space as a social construct through which people form expectations and regulate access and behavior, that is, Territoriality. Beyond proxemics, Human–Robot Interaction lacks the theoretical models and shared vocabulary needed to support empirical research on this dimension. To address this gap, we adapt insights from environmental psychology to develop NOX (ENtry, Occupancy, EXit), a stage-based model of human–robot territorial dynamics. NOX pinpoints sources of robot territorial infringement (i.e., friction points) which were validated in a between-subjects vignette study (N = 290). Our findings indicate that mismatches between robot behavior and human expectations at these friction points are associated with more negative affect, higher defensive intent, and lower perceived appropriateness. NOX clarifies this facet of human--robot spatial relationship and identifies future directions for design and research toward harmonious integration in human environments.