quiz answers carry a confidence slider — raw probability, snapped 0/30/50/70/90/100

Owner design round 2026-10-01: every multiple-choice quiz answer now
carries the learner's stated probability that his selected answer is
correct — calibration data for the prober and teacher, the flow itself
unchanged.

Definition (owner ruling, after weighing chance-normalization): RAW
probability. Sub-chance reports are diagnostic gold, not dead space —
'picked an option, believes it wrong' is a real state. The agents get
the sophistication: new shared/25-confidence.md composes for both
agents (chance level, sub-chance = distrusts the pick, correct+low =
fragile, wrong+high = committed misconception, IDK = genuine gap).

- question-core: AnswerRequest/QuestionAnswerData.confidence (quiz
  only, optional — old records valid), buildAnswer clamps and drops it
  on dontKnow, formatAnswerMessage states the line, CONFIDENCE_STOPS +
  DEFAULT_CONFIDENCE_INDEX exported.
- question-dock: snapped slider below 'I don't know', above 'Your
  thinking' — native range over the stop INDEX so ←/→ step the uneven
  grid cleanly, Tab chain rows → slider → thinking, Enter submits from
  the slider too. Rests at 50 and always sends (owner: 50 must mean a
  real coin flip, never 'untouched'). 'I don't know' GRAYS it out —
  layout holds, no value sent.

Deliberately untouched: explain free-recall card (quiz-only scope),
answered-card rendering of confidence, ask flow.

components/question-dock.tsx

@@ -9,6 +9,8 @@ import { cn } from "@/lib/utils";
 import {
 	buildAnswer,
 	coerceCorrectAnswer,
+	CONFIDENCE_STOPS,
+	DEFAULT_CONFIDENCE_INDEX,
 	emptyDockSelection,
 	normalizeOptions,
 	resolveCorrect,
@@ -264,6 +266,12 @@ function QuestionDockForm({
 	const [thinking, setThinking] = useState("");
 	const [other, setOther] = useState("");
 	const [text, setText] = useState("");
+	// Confidence (owner, 2026-10-01): an index into CONFIDENCE_STOPS,
+	// resting at 50 — a real coin flip by definition, untouched or
+	// deliberate (the same number, the same meaning). The dock unmounts
+	// between questions, so each question starts fresh at 50.
+	const [confIdx, setConfIdx] = useState<number>(DEFAULT_CONFIDENCE_INDEX);
+	const confidenceRef = useRef<HTMLInputElement>(null);
 	const selectMode: SelectMode = qd.mode === "multi-select" ? "multi-select" : "single-select";
 
 	// The PRIMARY dictation input (owner, STT round 1): while a question
@@ -297,6 +305,9 @@ function QuestionDockForm({
 			other: sel.otherSelected ? other : undefined,
 			text: qd.mode === "text" ? text : undefined,
 			note: qd.mode !== "text" ? thinking.trim() || undefined : undefined,
+			// Always sent on quiz answers (owner: 50 must mean 50, never
+			// "untouched"); buildAnswer drops it on "I don't know".
+			confidence: kind === "quiz" ? CONFIDENCE_STOPS[confIdx] : undefined,
 		};
 		onSubmit(buildAnswer(qd, req));
 	};
@@ -368,14 +379,19 @@ function QuestionDockForm({
 			// Alt/Cmd/Ctrl combos are never ours (Alt+arrows cycle sessions
 			// globally — they must not ALSO walk the question rows).
 			const modded = e.altKey || e.metaKey || e.ctrlKey;
-			// Plain Tab toggles focus: rows → thinking, anything else → the
-			// walked (or first) row. Shift+Tab falls through (the global
-			// thinking-level cycle owns it), so the shift check matters.
+			// Plain Tab walks the dock's focus chain forward: rows →
+			// confidence slider (quiz, when enabled) → thinking. Shift+Tab
+			// falls through (the global thinking-level cycle owns it), so the
+			// shift check matters.
 			if (e.key === "Tab" && !e.shiftKey && !modded) {
 				e.preventDefault();
 				e.stopPropagation();
-				if (t?.closest?.("[data-kbdrow]")) thinkingRef.current?.focus();
-				else {
+				if (t?.closest?.("[data-confidence]")) thinkingRef.current?.focus();
+				else if (t?.closest?.("[data-kbdrow]")) {
+					const slider = confidenceRef.current;
+					if (slider && !slider.disabled) slider.focus();
+					else thinkingRef.current?.focus();
+				} else {
 					const idx = kbdIdx ?? 0;
 					setKbdIdx(idx);
 					focusRow(idx);
@@ -573,6 +589,59 @@ function QuestionDockForm({
 				)}
 			</div>
 
+			{/* Confidence (owner, 2026-10-01): a snapped slider below the options
+			    and above "Your thinking" — the learner's stated probability
+			    that his selected answer is correct. ←/→ move it (native range
+			    semantics over the stop INDEX, so the uneven grid steps
+			    cleanly). "I don't know" GRAYS it out — the layout holds, no
+			    value is sent, the IDK signal stands alone. */}
+			{kind === "quiz" && (
+				<div className="border-t border-border/60 px-4 py-2.5">
+					<div className="flex items-center gap-3">
+						<span
+							className={cn(
+								"shrink-0 text-xs font-medium uppercase tracking-wide",
+								sel.dontKnow ? "text-muted-foreground/50" : "text-muted-foreground",
+							)}
+						>
+							Confidence
+						</span>
+						<input
+							ref={confidenceRef}
+							type="range"
+							min={0}
+							max={CONFIDENCE_STOPS.length - 1}
+							step={1}
+							value={confIdx}
+							disabled={sel.dontKnow}
+							aria-label="Confidence — the probability your selected answer is correct"
+							title="The probability your selected answer is correct — 50% is a coin flip"
+							data-testid="confidence-slider"
+							data-confidence=""
+							onChange={(e) => setConfIdx(Number(e.target.value))}
+							onKeyDown={(e) => {
+								// Enter submits from here too (dock-wide intuition);
+								// arrows stay native — ←/→ step the stop index.
+								if (e.key === "Enter" && canSubmit) {
+									e.preventDefault();
+									submit();
+								}
+							}}
+							className="h-1.5 min-w-0 flex-1 accent-primary disabled:opacity-40"
+						/>
+						<span
+							data-testid="confidence-value"
+							className={cn(
+								"w-9 shrink-0 text-right font-mono text-sm tabular-nums",
+								sel.dontKnow && "text-muted-foreground/50",
+							)}
+						>
+							{sel.dontKnow ? "—" : `${CONFIDENCE_STOPS[confIdx]}%`}
+						</span>
+					</div>
+				</div>
+			)}
+
 			{/* The learner's half of the dock — a composer TWIN: a labeled, bordered
 			    field with Submit docked inside, exactly like the chat composer's
 			    send. Select modes get "Your thinking" (Enter makes a newline — it

src/agent/prompts/shared/25-confidence.md

@@ -0,0 +1,11 @@
+## Confidence — reading the learner's self-assessment
+
+Every quiz answer arrives with a `Confidence: N%` line: the learner's stated probability that his selected answer is correct, set on a snapped slider (0, 30, 50, 70, 90, 100). This is calibration data, not decoration. Read it against the verdict:
+
+- 50 is a genuine coin flip. 90–100 claims certainty; 0–30 claims real doubt.
+- For an n-option question, chance is 1/n. Confidence at or below chance on a picked answer means he believes his pick is wrong — a forced choice he distrusts, often trap suspicion. Treat it as honesty, not error.
+- Correct + high confidence: solid knowledge — move on.
+- Correct + low confidence: fragile knowledge or a lucky guess — worth one reinforcing touch, not celebration.
+- Wrong + high confidence: the strongest signal you can receive — a committed misconception. Name the crack, probe it gently, and re-teach around it.
+- Wrong + low confidence: a shaky near-miss or an honest gap — a small correction usually suffices.
+- "I don't know" carries no confidence line: he declined to guess. A genuine gap, never a wrong answer.

src/core/question-core.ts

@@ -350,6 +350,7 @@ export interface QuestionAnswerData {
 	other?: string; // ask: "Other" free text
 	text?: string; // ask/explain: text-mode answer
 	note?: string;
+	confidence?: number; // quiz only: the learner's stated probability (0-100, raw) that his selected answer is correct — never sent on "I don't know" (owner, 2026-10-01)
 	correct?: boolean; // quiz only
 	correctIndices?: number[]; // quiz only (rendering)
 	committed?: string; // explain only (rendering): the model's committed answer
@@ -375,8 +376,17 @@ export interface AnswerRequest {
 	other?: string; // ask "Other"
 	text?: string; // ask text-mode
 	note?: string;
+	confidence?: number; // quiz only: 0-100 raw probability — 50 is a real coin flip, always sent (owner, 2026-10-01)
 }
 
+/** The confidence slider's snap stops (owner, 2026-10-01): raw probability
+ *  that the selected answer is correct, uneven on purpose — resolution
+ *  concentrates at the top where the calibration signal lives (90 vs 100
+ *  separates knows from mastered). 50 is a genuine coin flip and the
+ *  resting default — untouched and deliberate 50 are the same number. */
+export const CONFIDENCE_STOPS: readonly number[] = [0, 30, 50, 70, 90, 100];
+export const DEFAULT_CONFIDENCE_INDEX = 2;
+
 // ─── dock selection (the client state machine, pure for tests) ─────────────
 
 /** The question dock's selection state (0-based indices in display order). */
@@ -571,7 +581,6 @@ export function buildAnswer(qd: QuestionData, req: AnswerRequest): QuestionAnswe
 		note: req.note?.trim() || undefined,
 		answeredAt: new Date().toISOString(),
 	};
-
 	// resolve selected option values → OptionAnswer (in display order)
 	if (req.values && req.values.length > 0) {
 		const byValue = new Map(qd.options.map((o, i) => [o.value, { ...o, index: i + 1 }]));
@@ -589,6 +598,12 @@ export function buildAnswer(qd: QuestionData, req: AnswerRequest): QuestionAnswe
 		base.correctIndices = qd.correctIndices ?? [];
 		base.explanation = qd.explanation;
 		base.correct = base.dontKnow ? false : isCorrect(base.answers.map((a) => a.index), qd.correctIndices ?? []);
+		// The confidence slider rides on real quiz answers only — never on
+		// "I don't know" (no answer, no probability). Clamped defensively;
+		// the dock snaps to the grid, the record accepts any integer.
+		if (!base.dontKnow && req.confidence !== undefined) {
+			base.confidence = Math.max(0, Math.min(100, Math.round(req.confidence)));
+		}
 	}
 	if (qd.kind === "explain") {
 		// No client grading — the model grades in its reply, against the
@@ -620,6 +635,9 @@ export function formatAnswerMessage(ad: QuestionAnswerData): string {
 			const selectedStr = ad.answers.map((a) => `${a.index}. ${a.label}`).join(", ");
 			lines.push(`Selected: ${selectedStr || "(none)"}`);
 			lines.push(`Result: ${verdict}`);
+			if (ad.confidence !== undefined) {
+				lines.push(`Confidence: ${ad.confidence}% — the learner's stated probability that his selected answer is correct.`);
+			}
 		}
 		lines.push(`Correct: ${correctStr}`);
 	} else if (ad.kind === "explain") {

tests/prompt-overrides.test.ts

@@ -179,6 +179,7 @@ describe("the source-derived segment list", () => {
 				"system-prompt.md",
 				"prober/10-probe-doctrine.md",
 				"shared/20-question-tools.md",
+			"shared/25-confidence.md",
 				"shared/30-learner-files.md",
 				"shared/40-formatting.md",
 			],

tests/question-core.test.ts

@@ -12,6 +12,8 @@ import {
 	askOptionProblems,
 	buildAnswer,
 	coerceCorrectAnswer,
+	CONFIDENCE_STOPS,
+	DEFAULT_CONFIDENCE_INDEX,
 	findPendingQuestion,
 	formatAnswerMessage,
 	isCorrect,
@@ -337,6 +339,13 @@ function quizData(overrides?: Partial<QuestionData>): QuestionData {
 	};
 }
 
+describe("confidence stops", () => {
+	it("the owner-decided grid (2026-10-01): resolution concentrates at the top", () => {
+		assert.deepEqual(CONFIDENCE_STOPS, [0, 30, 50, 70, 90, 100]);
+		assert.equal(CONFIDENCE_STOPS[DEFAULT_CONFIDENCE_INDEX], 50, "rests at a real coin flip");
+	});
+});
+
 describe("buildAnswer", () => {
 	it("grades a correct selection", () => {
 		const ad = buildAnswer(quizData(), { values: ["mercury"] });
@@ -368,6 +377,22 @@ describe("buildAnswer", () => {
 		assert.deepEqual(ad.answers.map((a) => a.value), ["mercury"]);
 	});
 
+	// Confidence (owner, 2026-10-01): the slider's raw probability rides on
+	// real quiz answers only — never on "I don't know" (no answer, no
+	// probability), never on ask/explain. Clamped defensively.
+	it("carries confidence on quiz answers and clamps out-of-range values", () => {
+		assert.equal(buildAnswer(quizData(), { values: ["mercury"], confidence: 90 }).confidence, 90);
+		assert.equal(buildAnswer(quizData(), { values: ["mercury"], confidence: 150 }).confidence, 100);
+		assert.equal(buildAnswer(quizData(), { values: ["mercury"], confidence: -5 }).confidence, 0);
+		assert.equal(buildAnswer(quizData(), { values: ["mercury"] }).confidence, undefined);
+	});
+
+	it("drops confidence on dontKnow and on non-quiz kinds", () => {
+		assert.equal(buildAnswer(quizData(), { dontKnow: true, confidence: 70 }).confidence, undefined);
+		const ask = quizData({ kind: "ask", correctIndices: undefined, explanation: undefined });
+		assert.equal(buildAnswer(ask, { other: "x", confidence: 70 }).confidence, undefined);
+	});
+
 	it("multi-select grades as exact-set", () => {
 		const multi = quizData({
 			mode: "multi-select",
@@ -412,6 +437,13 @@ describe("formatAnswerMessage", () => {
 		assert.match(formatAnswerMessage(ad), /Note: guessed/);
 	});
 
+	it("states the confidence line on answered quizzes, absent on dontKnow", () => {
+		const ad = buildAnswer(quizData(), { values: ["mercury"], confidence: 70 });
+		assert.match(formatAnswerMessage(ad), /Confidence: 70% — the learner's stated probability that his selected answer is correct\./);
+		const idk = buildAnswer(quizData(), { dontKnow: true, confidence: 70 });
+		assert.ok(!formatAnswerMessage(idk).includes("Confidence:"));
+	});
+
 	it("formats ask answers", () => {
 		const ask = quizData({ kind: "ask", correctIndices: undefined, explanation: undefined });
 		const ad = buildAnswer(ask, { other: "whatever" });