Metrics

The comparison table in the summary report is only useful if you know what each column measures. The definitions below match what arcade.viz.report writes into summary_report. Read this page before you treat a ranking as final, especially on multi-qubit joint labels where a single wrong bit order can quietly destroy the headline number.

Joint accuracy

Joint accuracy is the fraction of shots where the full multi-qubit label matches the ground truth. For five qubits with joint labels this is a thirty-two class problem. Joint accuracy is the primary ranking key in the recommendation box on the executive report page.

A wrong data.qubit_bit_order systematically destroys joint accuracy while per-qubit numbers can still look plausible. The zoo default is lsb0. Several paper YAML files use msb0. Do not mix those conventions silently across configs you intend to compare.

Infidelity

Infidelity is typically one minus accuracy, or a closely related report variant. It is useful when you think in error rates, for example when binding a classifier score into stim as a readout error probability.

F5Q

F5Q is an aggregate of per-qubit fidelities, using a product or geometric-style combination in the zoo report. F5Q can look healthy even when one qubit is weak if the others are excellent. Always read it next to PQ min before declaring balance across the device.

PQ min and per-qubit fidelity

PQ min is the worst single-qubit assignment fidelity. Per-qubit fidelity columns show each qubit separately. Use these to spot imbalance. A method can win joint accuracy while harming one qubit that your algorithm cares about.

Hardware columns: LUT, DSP, and latency

These columns are analytical estimates from arcade.hardware. They are not post-place-and-route guarantees. They exist so you can reject a half-percent accuracy win that costs an order of magnitude more look-up tables. Scope and limits are explained in Hardware limits.

Duration and sweep curves

When sweep.enabled is true, ARCADE truncates traces at several lengths and plots speed against fidelity. Shorter readout usually raises error. The curve is how you find a knee before binding into QEC cycle time. See FTQC bridge for that next layer of reasoning.