# QA Results: Personalization Correctness Verification

## Overall Verdict: PASS

All QA plan steps executed successfully.

## Step 1: New test suite

```
cargo test --manifest-path tidal/Cargo.toml --test pg1_personalization_correctness -- --nocapture
```

```
running 16 tests
test dimension_mismatch_is_noop ... ok
test adaptive_learning_rate_decays ... ok
test ema_matches_manual_computation ... ok
test one_hour_window_exact_count ... ok
test decay_score_zero_after_many_half_lives ... ok
test more_engagement_ranks_higher ... ok
test all_time_count_monotonic ... ok
test gate_below_threshold_excluded ... ok
test multi_event_decay_matches_analytical ... ok
test velocity_equals_count_over_duration ... ok
test single_event_decay_matches_analytical ... ok
test out_of_order_converges_to_in_order ... ok
test signal_immediately_visible_in_retrieve ... ok
test interaction_boost_is_additive ... ok
test no_nan_or_infinity_in_scores ... ok
test max_per_creator_enforced ... ok

test result: ok. 16 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s
```

**Result: PASS** -- 16/16 tests pass, 0 failures, execution time 0.02s.

## Step 2: Lib regression check

```
cargo test --manifest-path tidal/Cargo.toml --lib
```

```
test result: ok. 1352 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 5.01s
```

**Result: PASS** -- 1352 lib tests pass, no regressions.

## Step 3: Format and lint

```
cargo fmt --manifest-path tidal/Cargo.toml -- --check tidal/tests/pg1_personalization_correctness.rs
```

**Result: PASS** -- No formatting diffs in our test file. (Other files from unrelated features have pre-existing fmt issues.)

```
cargo clippy --manifest-path tidal/Cargo.toml --test pg1_personalization_correctness -- -D warnings
```

**Result: PASS** -- No clippy warnings from `pg1_personalization_correctness.rs`. (Pre-existing warnings exist in other lib source files from unrelated features.)

## Step 4: Non-trivial assertion review

| Check | Verified |
|-------|----------|
| Decay tests use different timestamps (1s intervals) and varied weights (0.5 to 5.0) | YES |
| Multi-event test uses 10 events with non-uniform weights | YES |
| Out-of-order test shuffles chronological vs reverse order | YES |
| Score ordering uses 20 vs 5 views (4x difference) | YES |
| Reactivity test measures wall-clock with `Instant::now()` and asserts < 100ms | YES |
| Gate test has items at 10, 3, and 5 views (above/below/at boundary) | YES |
| NaN/Inf test includes edge cases: zero signals, 1e15 weight, 1e-15 weight | YES |
| Diversity test uses 5 creators x 5 items with graduated engagement | YES |

**Result: PASS** -- All assertions are non-trivial and exercise meaningful variation.

## QA Checklist

| # | Check | Expected | Actual | Status |
|---|-------|----------|--------|--------|
| 1 | pg1_personalization_correctness tests all pass | 0 failures | 0 failures | PASS |
| 2 | Lib tests pass (no regression) | 1352 | 1352 | PASS |
| 3 | `cargo fmt --check` clean for test file | No diffs | No diffs | PASS |
| 4 | `cargo clippy --tests` clean for test file | No warnings | No warnings | PASS |
| 5 | Decay tests use varied inputs | Confirmed | Confirmed | PASS |
| 6 | Ordering tests compare different signal profiles | Confirmed | Confirmed | PASS |
| 7 | Reactivity tests include timing assertions | Confirmed | Confirmed | PASS |