Common questions about using the SFR framework.
This document answers questions that organizations commonly ask when first engaging with the SFR framework. Answers use standards-oriented language and are designed to clarify what the framework does and does not do, before an organization invests time in detailed review.
SFR is a classification framework, not a certification body. It defines the criteria and evaluation methodology that determine whether a simulation system classifies as In-the-Loop, Surface-Level, or Out-of-the-Loop. A classification is a structural description of the system, not an endorsement or approval.
There is no SFR certificate, SFR label, or SFR approval that can be applied to a product. A system that meets the structural criteria of In-the-Loop classification can be accurately described as meeting those criteria, with the evidence to support the description. That description is not a certification.
See Adoption Roadmap for the stages through which the framework might develop additional institutional structures in future versions.
Aviation, military, motorsport, and rehabilitation programs each operate within existing regulatory and institutional frameworks for training qualification. SFR is a supplementary analysis tool that addresses a specific question those existing frameworks do not fully address: whether the simulation system being used is structurally capable of delivering physics-accurate motion cues.
Existing qualification frameworks typically define minimum equipment requirements, performance standards, and instructor qualifications. SFR addresses the physics-fidelity structural layer below those requirements. It informs decisions about which simulation systems are appropriate for which training objectives — it does not replace the frameworks within which those decisions are made.
A simulation system without any motion system classifies as Out-of-the-Loop under the SFR framework. This is not a negative judgment — it is an accurate structural description. Out-of-the-Loop systems are appropriate for many training objectives, particularly those focused on visual-cognitive tasks, procedure rehearsal, and environmental familiarization that do not depend on vestibular feedback.
The SFR framework's three-tier classification (In-the-Loop / Surface-Level / Out-of-the-Loop) exists specifically to distinguish between these three structural types, enabling organizations to select systems appropriate for their training objectives without the assumption that motion systems are always required or always correct.
A static system — one with no physics-derived motion delivered to the participant — does not meet the structural requirements for Criterion A (Causative Accuracy) or Criterion B (Temporal Coherence), because there is no motion to evaluate for causative origin or timing. The evaluation of a static system under SFR confirms that no motion is present, which produces an Out-of-the-Loop classification by structural default.
An organization that wants to document its static simulator's classification for procurement comparisons, research purposes, or training protocol documentation can do so using SFR. The evaluation for a static system requires less evidence than an in-the-loop system evaluation — primarily architecture documentation confirming the absence of physics-derived motion output.
The SFR Medical Risk Framework provides supplementary analysis of why surface-level simulation may present different risk profiles for neurologically compromised participants compared to healthy populations. This analysis is informative — it describes sensory conflict mechanisms and identifies populations that may be more sensitive to them — but it is not clinical guidance.
A rehabilitation program that classifies its simulation environment using SFR criteria has a structural description of the sensory conflict profile that environment may produce. This description can inform screening decisions. It does not replace the judgment of qualified medical professionals for individual patient assessment.
The Neurological Reserve and Compensation Demand document provides additional context on the theoretical basis for neurological sensitivity to simulation sensory conflict.
The SFR framework is explicitly designed to be referenceable in research. The Canonical Definitions provide a precise vocabulary for describing simulation system properties. The classification system provides a structural variable for describing study subjects. The Citation Guidelines provide formatting for referencing SFR in research papers, technical reports, and other document types.
Research organizations should note that SFR v0.9 Draft is a proposed standard and has not been ratified by a named governance authority. References to SFR in research should accurately reflect this status. The Research Reference Framework provides suggested language for describing the framework's status in methods sections and acknowledgments.
Research organizations that apply SFR classification to their study subjects and publish those results contribute to the community review process that advances the framework toward ratification.
SFR is a classification and evaluation framework. It provides a vocabulary, a set of structural criteria, an evaluation methodology, and an adoption pathway. It does not certify products, license evaluators, govern organizations, or replace existing training standards.
What SFR provides is a shared basis for asking and answering a question that existing frameworks leave largely unanswered: is this simulation system structurally capable of producing the physics-accurate sensory cues that make training transfer from simulation to reality? That question is answerable. SFR defines how to answer it.