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Solar-eclipse observation reports matched by computation, by source
'日食' articles of the Goryeosa treatise, the Jeolyo, the Sillok and the Ilgi, classified by type with codebook v2; the metric is the share of observation reports whose date lies within ±1 day of a computed eclipse visible at that source's site (Gaeseong or Seoul).
Across the three sources, seven to nine in ten eclipse observation reports match a computed eclipse visible at the observing site. Goryeosa scores above the Sillok: a treatise is an observation ledger, the Sillok a political record. Do not quote a match rate for all '日食' articles without classifying them by type.
- Formula
- Per type: matched / dated articles of the type. Eclipses computed from DE406 at the 12,282 new moons of 918–1910 for both sites, testing disc overlap above the horizon. Window ±1 day, ±0 shown too. Ilgi articles of the same day are also pooled to day level.
- How to read it
- The observation-report value is the headline. Forecast, ritual and discussion types include eclipses that were never visible (below the horizon, abroad, in the future), so lower rates there are expected; 'other' (not an eclipse at all) should sit near zero — it serves as a check on the coders.
- Caveats
- The 332 Sillok articles were re-coded from v1 (1.0) to v2; observation reports went from 84 to 77 (eight below-horizon computations moved to forecast). Before 1392, ΔT is a model value with a standard error of about one minute around the year 1000 (Morrison & Stephenson 2004, σ = 0.8t², t in centuries from 1820): no effect on day-level matching, but borderline horizon visibility calls can move. A manual check against the KASI historical-astronomy database did not make it into this version.
- External check
- Lee et al. 2016 (JKAS 49(4): 163–173; 228 and 222 on p. 163, the 222 records listed in Appendix A, pp. 169–173) matched 222 of 228 Goryeosa lunar-eclipse records to computation; Ahn & Lee 2004 (JASS 21(4): 493–504, Table 1 on p. 495) counted 231 Sillok solar records plus 30 from other histories, by event. This site counts articles.
- Reliability card
- externalExternal match — compared with an astronomical computation
Goryeosa treatise: 95 of 115 observation reports within ±1 day = 82.6% (Wilson 95% 74.7%–88.5%); same day 81.7%.
Jeolyo: 91 of 113 observation reports within ±1 day = 80.5% (Wilson 95% 72.3%–86.8%); same day 79.6%.
Sillok: 56 of 77 observation reports within ±1 day = 72.7% (Wilson 95% 61.9%–81.4%); same day 72.7%.
Ilgi: 52 of 57 observation reports within ±1 day = 91.2% (Wilson 95% 81.1%–96.2%); same day 89.5%.
Classification by type: 1,483 articles of the four sources coded in 15 batches (language-model coders); 150 blind re-coded — coder-to-coder agreement 92.7%, κ = 0.90 (κ = 1.00 pooled into observation / not observation / not an eclipse); κ = 0.96 once the editing rules (回咨, 齋戒; 1.2.1–1.2.3) are applied to both sides. Sillok v1→v2 agreement 90.1%.
| Source | Type | Articles | Dated articles | Match ±1 d | Share | 95% lo | 95% hi | Same day |
|---|---|---|---|---|---|---|---|---|
| Goryeosa treatise | discussion | 1 | 0 | 0 | ||||
| Goryeosa treatise | not occurred | 12 | 12 | 7 | 58.3% | 32.0% | 80.7% | 58.3% |
| Goryeosa treatise | observation | 116 | 115 | 95 | 82.6% | 74.7% | 88.5% | 81.7% |
| Goryeosa treatise | observation (day level) | 115 | 115 | 95 | 82.6% | 74.7% | 88.5% | |
| Jeolyo | discussion | 1 | 0 | 0 | ||||
| Jeolyo | forecast | 1 | 0 | 0 | ||||
| Jeolyo | not occurred | 11 | 11 | 5 | 45.5% | 21.3% | 72.0% | 45.5% |
| Jeolyo | observation | 115 | 113 | 91 | 80.5% | 72.3% | 86.8% | 79.6% |
| Jeolyo | observation (day level) | 113 | 113 | 91 | 80.5% | 72.3% | 86.8% | |
| Jeolyo | not an eclipse | 1 | 0 | 0 | ||||
| Sillok | discussion | 140 | 131 | 4 | 3.1% | 1.2% | 7.6% | 0.0% |
| Sillok | forecast | 44 | 44 | 5 | 11.4% | 5.0% | 24.0% | 0.0% |
| Sillok | not occurred | 8 | 8 | 5 | 62.5% | 30.6% | 86.3% | 62.5% |
| Sillok | observation | 77 | 77 | 56 | 72.7% | 61.9% | 81.4% | 72.7% |
| Sillok | observation (day level) | 77 | 70 | 51 | 72.9% | 61.5% | 81.9% | |
| Sillok | not an eclipse | 44 | 44 | 0 | 0.0% | 0.0% | 8.0% | 0.0% |
| Sillok | ritual | 19 | 18 | 7 | 38.9% | 20.3% | 61.4% | 33.3% |
| Ilgi | discussion | 315 | 314 | 31 | 9.9% | 7.0% | 13.7% | 2.2% |
| Ilgi | forecast | 37 | 37 | 3 | 8.1% | 2.8% | 21.3% | 5.4% |
| Ilgi | observation | 57 | 57 | 52 | 91.2% | 81.1% | 96.2% | 89.5% |
| Ilgi | observation (day level) | 57 | 51 | 46 | 90.2% | 79.0% | 95.7% | |
| Ilgi | not an eclipse | 312 | 312 | 2 | 0.6% | 0.2% | 2.3% | 0.0% |
| Ilgi | ritual | 172 | 172 | 56 | 32.6% | 26.0% | 39.9% | 20.9% |