Compatibility Screening¶
Checklist — instantiates Interaction Effect Mapping
A checklist, rule set, or review procedure that filters unsafe, invalid, infeasible, or uninterpretable combinations.
Compatibility Screening is the guardrail that runs before any interaction is mapped: a checklist of coexistence rules that removes combinations which must not be tested or deployed — unsafe, invalid, infeasible, or uninterpretable ones. Its defining question is narrow and binary: can these coexist at all? It never asks what does coexistence do? — it produces no interaction estimate, no synergy or antagonism label, only a pass/fail gate. That narrowness is the point. By pruning the forbidden and impossible pairings up front, it shrinks the combination space the mapping mechanisms have to explore and keeps testers from running combinations that would harm a system, violate a constraint, or yield results no one can interpret. It is a filter on the domain of the map, not an entry in the map itself.
Example¶
A chemistry teaching lab is preparing a batch of student experiments that each combine two reagents from a shared stockroom. Before any combination is scheduled, the lab runs it through a compatibility screen — a rule set drawn from a reactivity chart. Each candidate pair is checked against categorical rules: oxidizer with organic fuel → forbidden (fire/explosion risk); strong acid with cyanide salt → forbidden (toxic gas); two inert buffers → allowed; a reactive pair that is safe only under a fume hood → allowed with control.
The screen's output is not a ranking of which pairs react most interestingly — that is a different question entirely. It is a filtered list: dozens of candidate pairings enter, the handful that are hazardous or nonsensical are struck out, and only the coexistence-safe remainder is passed downstream to be actually studied. A pair that fails the screen is never tested, no matter how scientifically curious it looks. When the stockroom adds a new reagent, the screen is re-run so its interactions with everything already on the shelf are gated before it enters any experiment.
How it works¶
- Enumerate the candidates. List the factors and the pairings under consideration — the population the screen will filter.
- Apply coexistence rules. Check each pairing against safety, validity, feasibility, and interpretability rules; each returns pass, fail, or pass-with-control.
- Filter, don't rank. Remove the failures and hand the surviving set downstream; the screen assigns no effect and no interaction type.
- Re-screen on change. When a new factor is introduced or a constraint changes, re-run the checklist so nothing unsafe slips into the map through the side door.
Tuning parameters¶
- Rule strictness — how conservative the fail threshold is. Stricter rules prune more aggressively (fewer surprises, but more potentially useful combinations excluded); looser rules admit more (broader map, more risk downstream).
- Category granularity — screening by broad hazard class versus by specific substance/configuration. Coarser classes are faster but over-exclude; finer rules are precise but heavier to maintain.
- Failure disposition — whether a failing pair is hard-forbidden, or allowed under a named control (containment, supervision, sandbox). More dispositions preserve options at the cost of a more complex rulebook.
- Re-screen trigger — what changes force a re-run (new factor, revised constraint, new regulation). Sensitive triggers keep the screen current but cost review cycles.
- Authority source — whether rules come from regulation, a reference chart, or expert judgment; the more authoritative the source, the more the pass/fail can be trusted without case-by-case debate.
When it helps, and when it misleads¶
Its strength is that it prevents the map from ever containing a combination that should not exist, and it makes the downstream mapping cheaper by shrinking the space to the admissible region — a necessary first pass in any safety-sensitive setting.[n1] It answers a real, decidable question — can these coexist? — quickly and defensibly.
Its failure mode is the seductive one: a pass is easily mistaken for a positive interaction result. "Compatible" means allowed to coexist, not good together — a screen that clears a bundle has said nothing about whether the bundle helps, harms, or interferes. The classic misuse is shipping a combination because it "passed compatibility," skipping the effect-mapping that would have found a quiet antagonism. Screening is necessary but never sufficient. The guarding discipline is to keep the screen strictly a gate — pass means admissible for mapping, never approved — and to hand every surviving combination to a mechanism that actually measures what it does.
How it implements the components¶
compatibility_check— is the core screen: the pass/fail coexistence test that admits or excludes each combination.factor_list— enumerates the factors and candidate pairings the screen is applied to.review_or_iteration_rule— the re-screen trigger that re-runs the checklist when a new factor or constraint enters.
It does not implement effect_measurement, interaction_type_classification, or design_update_rule — measuring what a combination does, labeling it synergy or antagonism, and prescribing a design response belong to the effect-mapping mechanisms such as Factorial Experiment and Interaction Matrix Table; this screen only gates admissibility.
Related¶
- Instantiates: Interaction Effect Mapping — guards the map's boundary by excluding inadmissible combinations.
- Sibling mechanisms: Factorial Experiment · Pairwise Combination Testing · Interaction Matrix Table · Dependency Interaction Map · Treatment Interaction Analysis · Design of Experiments Protocol
Editorial Notes¶
Form Classification¶
Form family: Decision, Gate & Allocation
Rationale: A checklist, rule set, or review procedure that filters unsafe, invalid, infeasible, or uninterpretable combinations, making its operative form a case-specific gate, selection, routing, prioritization, or disposition decision.
Independent corroboration: The frozen evidence defines Compatibility Screening as 'A checklist, rule set, or review procedure that filters unsafe, invalid, infeasible, or uninterpretable combinations', so its operative form is Decision, Gate & Allocation.
Review outcome: Independent reviewer agreement; high confidence.
Origin Attribution¶
Primary origin: Chemistry & Materials Science
Origin pattern: Cross-disciplinary synthesis
Present-day reach: Multi-domain
Rationale: Chemical handling established compatibility screens as pre-use gates against unsafe or reactive combinations.
Related originating lineages:
- Engineering & Design — Design verification generalized the screen to infeasible, invalid, and uninterpretable component combinations.
Review resolution: Both reviewers agree on chemistry_materials as primary. Reading the source mechanism confirms that its defining operation belongs to that lineage; the final record retains engineering_design only where it materially formed the mechanism and keeps present-day application breadth separate from provenance.
Encyclopedia synthesis: The exact catalogued form synthesizes established practice rather than reproducing a single standard historical label.
Review outcome: Reconciled after independent review; high confidence.
Notes¶
The screen sits upstream of the testing mechanisms: Pairwise Combination Testing and Design of Experiments Protocol consume its filtered set, so no covering array or design ever asks for a forbidden configuration. Keeping the screen distinct from the map is what preserves the archetype's core distinction — compatibility tells you whether coexistence is allowed, interaction mapping tells you what coexistence does.
[n1] A chemical compatibility (reactivity) chart is a matrix of which substance classes may not be mixed — the canonical example of a coexistence screen. It is a safety gate, not an effect analysis: it tells you a combination is forbidden, not what a permitted combination would accomplish. ↩