Metric comparability

Gramin does not collapse grammar quality into one score. A count can be mechanically comparable while its meaning still depends on how the author expressed the grammar.

Class	Meaning	UI treatment
A	Cross-format comparable under the metric definition	Show in the primary comparison
B	Context-dependent; capability or representation affects interpretation	Show with a context badge
C	Format-specific or heuristic	Keep in an advanced section

Examples include rule and alternative counts as Class A candidates, recursion and nullable analysis as context-dependent measurements, and format-specific sugar or precedence details as Class C measurements.

notApplicable is data

If a frontend cannot define a metric for its representation, the feature retains a notApplicable state and reason. The UI must not render that state as 0, because zero says the property was measured and absent.

Comparing revisions

Before comparing values, compare the representation context: frontend, capabilities, source identity, and relevant options. If that context changed, explain the context change before describing a number as an increase or decrease.

The normative definitions live in the metrics catalog and cross-format notes.