GEOS-FN-003 — Sentinel Signal Families for Foundational Numeracy
Version: 0.01 Status: Normative Standard
0. Interpretive Basis and Certification Intent ————————————————--
GEOS-FN-003 defines the Sentinel Signal Families that an Outcom Signal Portfolio must draw upon in order to be eligible for certification as a GEOS Certified Outcome Signal Portfolio (GeOSP™) for Foundational Numeracy.
This standard:
defines the design space of Outcome Signal Portfolios that are eligible for certification;
constrains certifiable artifacts only;
imposes no obligations, duties, or restrictions on any role defined in GEOS-CORE-001; an
does not limit what any School System may measure, publish, or use internally.
Certification under this standard is voluntary and applies solely to the Outcome Signal Portfolio submitted for assessment.
1. Purpose and Scope ————————
This document specifies the families of Sentinel signals that the GEOS Standards recognize as valid indicators of Foundational Numeracy outcomes for finance-grade use.
It defines:
the permitted families of Sentinel signals;
the relationship between signal families and outcome construct families defined in GEOS-FN-002;
acceptable statistical forms for Sentinel signals; and
forbidden constructions that undermine auditability, interpretability, or anti-gaming objectives.
This standard applies to all Sentinel signals included in an Outcome Signal Portfolio submitted for GEOS certification under GEOS-FN-001.
This document does not define:
assessment instruments;
item-level scoring rules;
funding thresholds;
signal weighting schemes; or
disbursement logic.
2. Design Principles ————————
Sentinel Signal Families defined in this standard reflect the following principles:
Portfolio primacy: no single signal is sufficient for finance-grade inference.
Anti-gaming by construction: structural diversity replaces reliance on incentives.
Auditability: every signal must be reconstructible from raw data.
Comparability: signals must support cross-jurisdictional interpretation without normalization to local curricula.
Non-normativity: signals describe observable outcomes, not desired pedagogy.
3. Sentinel Signal Families ——————————-
An Outcome Signal Portfolio eligible for certification MUST include Sentinel signals drawn from each of the following Sentinel Signal Families, subject only to the exception mechanism defined in Section 6.
Signals describing the distribution of learner status at a defined point in time.
Permitted forms include:
proportion of learners above or below defined cut points;
percentile or quantile distributions;
categorical band distributions.
Forbidden forms include:
single composite attainment indices; and
opaque proficiency scores without published derivation logic.
Signals describing change in learner performance over time.
Permitted forms include:
mean or median learning gain over a defined interval;
proportion of learners exhibiting positive growth;
transitions between performance bands across time points.
All Learning Progression Signals MUST specify:
baseline window;
follow-up window; and
elapsed instructional time or exposure proxy.
Signals derived from patterns in learner interaction or assessment responses.
Permitted forms include:
error pattern frequencies;
concept-specific success rates;
response consistency measures.
These signals MUST NOT be used to infer learner intent, effort, or motivation.
Signals describing learner facility across symbolic and non-symbolic numerical representations.
Permitted forms include:
success rates by representation type;
transition accuracy between representations; and
latency-adjusted response indicators where available.
Signals describing dispersion, volatility, or stability within defined cohorts.
Permitted forms include:
variance or interquartile range measures;
subgroup dispersion ratios; and
longitudinal stability indicators.
These signals support auditability and gaming detection rather than outcome valuation.
4. Signal Construction Rules ——————————--
All Sentinel signals included in a certifiable Outcome Signal Portfolio MUST:
be derived from conformant raw data streams as defined in GEOS-FN-001;
use reproducible and auditable construction rules;
publish sufficient metadata to enable independent reconstruction; and
remain interpretable without access to proprietary methods.
Signals MUST NOT:
embed weighting schemes that cannot be externally verified;
collapse multiple construct families into a single score; or
rely on discretionary adjustments.
5. Portfolio-Level Constraints ———————————-
An Outcome Signal Portfolio eligible for GEOS certification MUST include at least one Sentinel signal from each Sentinel Signal Family defined in Section 3.
No Sentinel Signal Family is optional by default.
No Sentinel signal defined under this standard is intended to be universal, sufficient, or decisive in isolation.
6. Narrow Exception Mechanism ———————————
An Outcome Signal Portfolio MAY omit one or more Sentinel Signal Families only where the portfolio explicitly documents the absence of the raw data required to construct signals in that family.
Where an omission occurs, the Outcome Signal Portfolio MUST include certification metadata specifying:
the Sentinel Signal Family omitted;
the specific raw data elements not available;
the reason the data are unavailable; and
the resulting limitation on portfolio scope and interpretability.
GEOS certification records MUST publicly indicate the presence or absence of each Sentinel Signal Family within a certified Outcome Signal Portfolio.
7. Relationship to Funding Decisions —————————————-
This standard:
does not prescribe which Sentinel signals are selected, disclosed, or acted upon in any funding decision;
does not constrain how any funding counterparty interprets certified artifacts; and
does not imply that inclusion of additional signals increases funding eligibility.
The GEOS Standards define only the permissible design space for certifiable artifacts.
8. Versioning and Evolution ——————————-
Revisions to Sentinel Signal Families:
MUST be versioned;
MUST preserve backward interpretability where feasible; and
MUST be justified through published methodological rationale.