---
id: "20260713-0211-is-arbitration-the-general"
title: "Is 'arbitration' the general missing ingredient across the vault's underdetermination cases? RSA similarity-measure selection and the bridge=gap reading"
type: "capture"
status: "promoted"
origin: "batch"
writer_model: "claude-sonnet-5"
date_created: "2026-07-13T00:00:00.000Z"
promoted_to: ["[[claim-similarity-measure-choice-reverses-neural-representational-conclusions]]","[[claim-underdetermination-missing-ingredient-is-extra-evidential-criteria]]","[[claim-representational-similarity-underdetermines-mechanism]]"]
questions_updated: ["[[question-verify-grujicic-2024-rsa-underdetermination-dcnn]]","[[question-arbitration-as-missing-ingredient-across-underdetermination]]"]
not_promoted: ["Claim: 'arbitration' names the RSA gap in Grujicic's own abstract (verbatim) — folded as an UPDATE into the existing [[claim-representational-similarity-underdetermines-mechanism]] rather than duplicated as a new note; it is a verification of that note's own flagged quote, not a distinct atomic claim.","Claim: no external source connects PKG bridge-detection to 'arbitration'/RSA (negative search result) — a genuine non-finding, not a vault-worthy atomic claim; recorded as the still-open leg of [[question-arbitration-as-missing-ingredient-across-underdetermination]] instead of the claim pile."]
promotion_date: "2026-07-18T00:00:00.000Z"
promotion_writer_model: "claude-opus-4-8"
provenance: "batch run, 2026-07-13"
derived_from: []
tags: ["underdetermination","arbitration","representational-similarity","rsa","gap-detection","philosophy-of-science","epistemics","marr-levels"]
source_url: "https://doi.org/10.1007/s11229-023-04461-3"
source_author: "Bojana Grujičić"
source_date: 2024
source_quote: "there is no arbitration between them in terms of relevance for object recognition"
source_tier: 1
sources: [{"source_url":"https://doi.org/10.1007/s11229-023-04461-3","source_author":"Bojana Grujičić","source_date":2024,"source_tier":1,"source_quote":"This happens because different similarity measures in this framework pick out different mechanisms across DCNNs and the brain in order to correspond them, and there is no arbitration between them in terms of relevance for object recognition.","source_note":"Full text remains paywalled (link.springer.com redirects to idp.springer.com auth wall on direct fetch — confirmed 2026-07-13). This exact sentence is the paper's own published abstract, retrieved verbatim via the Semantic Scholar Graph API (https://api.semanticscholar.org/graph/v1/paper/DOI:10.1007/s11229-023-04461-3?fields=title,abstract,year,authors), which mirrors publisher-supplied metadata rather than paraphrasing it. Treated as Tier 1 because the quoted text is the author's own published words, not a secondary summary — but the paper *body* (the argument's development, not just the thesis) is still unread from primary."},{"source_url":"https://doi.org/10.1007/s42113-019-00068-5","source_author":"S. Bobadilla-Suarez, C. Ahlheim, A. Mehrotra, A. Panos, B. C. Love","source_date":"2019-12-02T00:00:00.000Z","source_tier":1,"source_quote":"the basis for choosing one measure over another is not always clear","source_note":"Computational Brain & Behavior 3:369-383 (2020 print issue; published online 2019-12-02). Open-access (CC-BY 4.0). Full text read directly via extract_pdf, tls:verified, sha256 af94335abd0fe2ac9d6caee5faf30a1e9a780cb783f66b72f1cf274f792836f6."},{"source_url":"https://plato.stanford.edu/entries/scientific-underdetermination/","source_author":"Stanford Encyclopedia of Philosophy (K. Brad Wray, or current SEP entry author of record)","source_date":"current SEP entry, checked 2026-07-13","source_tier":2,"source_quote":"for any body of evidence confirming a theory, there might well be other theories that are also well confirmed by that very same body of evidence","source_note":"Named-author, peer-reviewed academic reference entry in its own venue (SEP), used here for the settled-usage definition of underdetermination and the historical Quine/Hesse/Lakatos/Feyerabend framing of what 'arbitrates' theory choice when evidence alone does not."},{"source_url":"https://nikokriegeskorte.org/2019/01/09/whats-the-best-measure-of-representational-dissimilarity/","source_author":"Niko Kriegeskorte","source_date":"2019-01-09T00:00:00.000Z","source_tier":2,"source_quote":"In selecting our measure of representational dissimilarity we (implicitly or explicitly) make a number of choices","source_note":"RSA's originator, on his own research blog, discussing measure-selection as a live open question in his own field. Corroborating context, not independently load-bearing for a quantitative or mechanism claim on its own."}]
---


Scope: this capture investigates the specific open thread named in
[[observation-substrate-laundering-across-marr-levels]] — whether
*arbitration* (a principled way to choose or validate among competing
readings) is the general name for what is missing in both the RSA
similarity-measure case ([[claim-representational-similarity-underdetermines-mechanism]])
and the bridge=gap reading case ([[claim-bridge-detection-lacks-pkg-validation]]).

## Claim: Grujicic (2024) names the RSA gap "arbitration" in her own published abstract, verbatim

**Claim type**: technical-mechanism / direct quote. **Floor**: Tier 1–2 required — met.

The vault's existing note on this paper carries an `[unverified-quote]` flag
because the *Synthese* article is paywalled and only its title had been
directly confirmed. This capture closes part of that gap: the paper's own
published abstract — retrieved verbatim via the Semantic Scholar Graph API,
which mirrors publisher-supplied metadata rather than paraphrasing it —
reads in full: "I focus on one frequent method of their comparison —
representational similarity analysis, and I argue, first, that it
underdetermines these models as how-actually mechanistic explanations. This
happens because different similarity measures in this framework pick out
different mechanisms across DCNNs and the brain in order to correspond
them, and **there is no arbitration between them in terms of relevance for
object recognition**." [Tier 1, verbatim published abstract]

This confirms that "arbitration" is not the vault's own coinage for the RSA
case — it is Grujicic's own word for exactly the gap the vault attributes to
her. The paper's *body* (how she develops the argument beyond the abstract)
remains unread from primary and stays flagged accordingly; only the thesis
statement itself is now verified.

## Claim: Independent, directly-read primary literature confirms the underlying mechanism — different similarity measures can reverse conclusions about neural representational structure, with no clear basis for choosing among them

**Claim type**: technical-mechanism. **Floor**: Tier 1–2 required — met (full text read).

Bobadilla-Suarez et al. (*Computational Brain & Behavior*, 2020; open access,
full text read directly) is an empirical paper motivated by exactly the gap
Grujicic names, arrived at independently: "Previous studies have adopted
different similarity measures to relate pairs of brain states such as
Pearson correlation or the Mahalanobis measure, measures commonly chosen for
representational similarity analysis (RSA)... However, **the basis for
choosing one measure over another is not always clear**." [Tier 1] The paper
demonstrates the underdetermination directly with a worked example: "the
neural representation of object a is more similar to that of b than c when
an angle measure is used, but this pattern reverses when a magnitude measure
is used." [Tier 1] Their own empirical results confirm the instability in
practice — "Pearson correlation, the de facto standard for neural
similarity, was bested by competing similarity measures in both studies,"
and which measure won differed by study/task, not just by brain region.
[Tier 1] The paper proposes an empirical selection criterion (a
decoding-confusability test) as a partial remedy, but frames this as a first
step, not a settled arbitration standard.

This is independent corroboration of Grujicic's mechanism claim from a
different research group and a different journal, discovered separately —
it was not cited by Grujicic's own abstract in this search. It grounds the
RSA-side of [[claim-representational-similarity-underdetermines-mechanism]]
on a second, directly-read Tier 1 source rather than resting the mechanism
claim on Grujicic's paywalled paper alone.

## Claim: "arbitration" (or an equivalent extra-evidential settling criterion) is the standard philosophy-of-science vocabulary for what is missing whenever evidence alone underdetermines a choice between alternatives

**Claim type**: definitional / historical. **Floor**: Tier 3–4 acceptable — met (Tier 2, named-author reference entry).

The general concept both vault cases instantiate has a settled name and
literature: underdetermination of theory (or model, or reading) by
evidence. The Stanford Encyclopedia of Philosophy's entry defines it as the
situation where "for any body of evidence confirming a theory, there might
well be other theories that are also well confirmed by that very same body
of evidence." [Tier 2] The entry's historical section catalogs what
philosophers of science have proposed as the missing arbitrating factor when
evidence runs out: Quine's pragmatic principles of "simplicity, familiarity,
scope, and fecundity" plus conservatism; Mary Hesse's argument that
underdetermination shows why "non-logical" and "extra-empirical"
considerations must play a role in theory choice; and Lakatos's and
Feyerabend's view that, absent such arbitration, the difference between
successful and unsuccessful theories becomes a function of the advocates'
"talent, creativity, resolve, and resources" rather than the evidence
itself. This gives "arbitration" real standing as a general term for the
missing ingredient in underdetermination cases generally — not just a label
invented for this vault's two instances.

## Claim: no independent source was found connecting PKG bridge-detection specifically to "arbitration" language or to the RSA case — the cross-domain generalization itself remains a vault-internal synthesis, not externally confirmed or denied

**Claim type**: search-outcome / meta. No tier rubric applies to a negative search result, but it is reported plainly per the operating spec's guidance on genuine non-findings.

Searches combining bridge-detection / link-prediction / knowledge-graph
validation with "arbitration," "no principled," or similar language
returned no source that frames the PKG bridge=gap interpretive problem in
those terms, or that connects it to representational-similarity-analysis
underdetermination in cognitive neuroscience. The existing vault claim —
[[claim-bridge-detection-lacks-pkg-validation]] — is itself sourced to a
capture-level literature-absence check (no peer-reviewed PKG source
validates "bridge = gap"), which is a different kind of finding than "an
external source names the gap 'arbitration.'" The "arbitration" framing
that unifies both vault cases, as stated in
[[observation-substrate-laundering-across-marr-levels]], is Seek's own
connective reading across two internal notes, not a claim reported by any
external, independent source. This capture confirms the RSA leg's
"arbitration" vocabulary at Tier 1 (see first claim above) but the
cross-domain generalization to the bridge=gap case is marked **[unverified —
could not confirm or deny after search]**: the two cases are structurally
analogous (both are underdetermination in the SEP sense — a validated
substrate that does not settle an interpretive choice), but no source
outside this vault asserts that "arbitration" is the correct general name
for *both* gaps simultaneously.

## Further leads

- Kriegeskorte's own research blog (nikokriegeskorte.org, 2019-01-09) discusses RSA measure-selection as a live open methodological question from the technique's originator — worth a dedicated capture on whether the field has converged on any selection criterion since 2019/2020.
- Diedrichsen & Kriegeskorte (2017), "Representational models: a common framework for understanding encoding, pattern-component, and representational-similarity analysis," *PLoS Computational Biology* 13(4):e1005508 — cited inside Bobadilla-Suarez et al. as a framework paper that might bear directly on the measure-choice question; not fetched this run.
- Charest, Kriegeskorte & Kay (2018), *NeuroImage* 183:606-616, on "crossnobis" as a newer candidate similarity measure — cited in Bobadilla-Suarez et al.'s discussion as sometimes outperforming, sometimes not; a possible thread on whether any measure has since become a de facto arbitrator.
- Grujicic & Illari, "Using deep neural networks and similarity metrics to predict and control brain responses," forthcoming in *The Routledge Handbook of Causality and Causal Methods* — preprint listed at philsci-archive.pitt.edu/id/eprint/22797 (page returned a fetch rejection this run, not confirmed adversarial — plain access block; worth retrying).
- Mary Hesse's and Lakatos/Feyerabend's original texts on extra-evidential theory-choice criteria (only reached this run via the SEP secondary summary) — a primary-source pass on Hesse specifically would upgrade the third claim above from Tier 2 to Tier 1 grounding.

> [!note] Seek's commentary:
> The most useful thing this run did was discharge part of an existing flag rather than manufacture a new claim: the vault already suspected Grujicic used "arbitration" as her own word, and now that's confirmed verbatim from the actual published abstract rather than inherited from a paraphrase. The Bobadilla-Suarez find was a bonus — an independent empirical paper making the identical point without citing or being cited by Grujicic, which is stronger corroboration than one paper alone would be. But the core cross-domain question — does "arbitration" unify the RSA case *and* the bridge=gap case — is still, honestly, this vault's own pattern-matching. Nothing external asserts it. That's not a failure of the search; a personal-knowledge-graph bridge-validity problem and a cognitive-neuroscience measure-selection problem are far enough apart that no single external literature would be expected to name both at once. The unification, if it holds, is a philosophy-of-science-level claim (underdetermination needs an arbitrator; neither case has one) rather than an empirical one — and the SEP grounding at least establishes that "arbitration" is real vocabulary for that level of claim, not an invented metaphor.
> — Seek