Table 1
Results of the data acquisition process, showing the properties retrieved from Wikidata and their absolute frequencies.
| IDENTIFIER | NAME | DESCRIPTION | FREQUENCY |
|---|---|---|---|
| P18 | image | image of relevant illustration of the subject […] | 36 179 |
| P1476 | title | published name of a work, such as a newspaper article […] | 29 077 |
| P170 | creator | maker of this creative work or other object […] | 33 616 |
| P571 | inception | time when an entity begins to exist […] | 35 588 |
| P31 | instance of | type to which this subject corresponds/belongs […] | 37 393 |
| P2048 | height | vertical length of an entity | 35 276 |
| P2049 | width | width of an object | 35 268 |
| P186 | made from material | material the subject or the object is made of or derived from […] | 66 651 |
| P135 | movement | literary, artistic, scientific or philosophical movement or scene […] | 2668 |
| P136 | genre | creative work’s genre or an artist’s field of work […] | 33 741 |
| P180 | depicts | entity visually depicted in an image, literarily described in a work […] | 62 848 |
| P921 | main subject | primary topic of a work or act of communication | 13 253 |
| P195 | collection | art, museum, archival, […] of which the subject is part […] | 56 189 |
| P276 | location | location of the object, structure or event […] | 41 557 |
| P17 | country | sovereign state that this item is in […] | 5712 |
| P495 | country of origin | country of origin of this item | 1210 |

Figure 1
Front-end design of iART. (a) On the left side of the GUI, users can access facets organized in expandable panels, while the right side displays the search results in an image grid. (b) For nuanced control of the search results, a modal dialog provides advanced configuration options.
Table 2
Mean results for concept extraction, tuple extraction, and relationship extraction in terms of precision (P), recall (R), and F1-score across different LLMs and prompting strategies. The averages are calculated over three iterations. The best-performing approach is indicated in bold.
| LLM | PROMPT | CONCEPT EXTRACTION | TUPLE EXTRACTION | RELATION EXTRACTION | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| P | R | F1 | P | R | F1 | P | R | F1 | ||
| Micro | ||||||||||
| Qwen3 | CoT | 0.808 | 0.859 | 0.833 | 0.721 | 0.725 | 0.723 | 0.468 | 0.471 | 0.469 |
| Role-CoT | 0.560 | 0.706 | 0.624 | 0.384 | 0.503 | 0.435 | 0.206 | 0.271 | 0.234 | |
| ReAct | 0.698 | 0.671 | 0.684 | 0.539 | 0.508 | 0.523 | 0.357 | 0.343 | 0.350 | |
| Gemma 3 | CoT | 0.776 | 0.857 | 0.815 | 0.639 | 0.665 | 0.652 | 0.422 | 0.448 | 0.435 |
| Role-CoT | 0.571 | 0.782 | 0.660 | 0.379 | 0.497 | 0.430 | 0.150 | 0.237 | 0.184 | |
| ReAct | 0.757 | 0.816 | 0.785 | 0.609 | 0.620 | 0.614 | 0.355 | 0.365 | 0.360 | |
| LLaMA 3.1 | CoT | 0.186 | 0.074 | 0.106 | 0.215 | 0.109 | 0.145 | 0.167 | 0.085 | 0.112 |
| Role-CoT | 0.503 | 0.362 | 0.421 | 0.444 | 0.294 | 0.354 | 0.260 | 0.179 | 0.212 | |
| ReAct | 0.393 | 0.205 | 0.269 | 0.391 | 0.217 | 0.279 | 0.265 | 0.147 | 0.189 | |
| Macro | ||||||||||
| Qwen3 | CoT | 0.789 | 0.857 | 0.802 | 0.710 | 0.687 | 0.684 | 0.524 | 0.518 | 0.511 |
| Role-CoT | 0.651 | 0.782 | 0.662 | 0.519 | 0.537 | 0.490 | 0.294 | 0.302 | 0.285 | |
| ReAct | 0.608 | 0.621 | 0.590 | 0.581 | 0.547 | 0.543 | 0.386 | 0.390 | 0.375 | |
| Gemma 3 | CoT | 0.781 | 0.867 | 0.795 | 0.614 | 0.625 | 0.591 | 0.404 | 0.440 | 0.404 |
| Role-CoT | 0.604 | 0.788 | 0.644 | 0.467 | 0.526 | 0.457 | 0.173 | 0.264 | 0.189 | |
| ReAct | 0.777 | 0.830 | 0.774 | 0.628 | 0.575 | 0.568 | 0.328 | 0.321 | 0.309 | |
| LLaMA 3.1 | CoT | 0.103 | 0.112 | 0.095 | 0.227 | 0.207 | 0.212 | 0.176 | 0.176 | 0.176 |
| Role-CoT | 0.325 | 0.357 | 0.326 | 0.382 | 0.327 | 0.340 | 0.223 | 0.224 | 0.218 | |
| ReAct | 0.192 | 0.195 | 0.179 | 0.329 | 0.288 | 0.300 | 0.260 | 0.239 | 0.246 | |
Table 3
Results for relation extraction across different LLMs and prompting strategies. For each model-prompt configuration, we report the number of concepts |ℂ|, the total number of predicted tuples |ℙ|, the total number of triplets (), the number of Iconclass notations with valid triplets (|ℕ|), the number without valid triplets (), and the mean number of triplets per Iconclass notations, i.e., .
| LLM | PROMPT | |ℂ| | |ℙ| | |ℕ| | |||
|---|---|---|---|---|---|---|---|
| Qwen3 | CoT | 241 | 162 | 164 | 71 | 14 | 2.3 |
| Role-CoT | 302 | 223 | 226 | 78 | 7 | 2.9 | |
| ReAct | 204 | 140 | 143 | 58 | 27 | 2.5 | |
| Gemma 3 | CoT | 256 | 182 | 186 | 83 | 2 | 2.2 |
| Role-CoT | 325 | 231 | 279 | 84 | 1 | 3.3 | |
| ReAct | 247 | 176 | 178 | 81 | 4 | 2.2 | |
| LLaMA 3.1 | CoT | 25 | 13 | 13 | 8 | 77 | 1.6 |
| Role-CoT | 131 | 67 | 72 | 35 | 50 | 2.1 | |
| ReAct | 57 | 24 | 24 | 11 | 74 | 2.2 |
Table 4
Qualitative comparison of ground-truth and predicted triplets (represented in the form subject-predicate-object) for selected Iconclass notations N, with associated descriptions DN shown in parentheses.
| N | GROUND TRUTH | PREDICTION | ||||
|---|---|---|---|---|---|---|
| SUBJECT | PREDICATE | OBJECT | SUBJECT | PREDICATE | OBJECT | |
| 93G (House of Sleep: a gloomy cave through which runs the river Lethe; possibly with two gates, […]) | ||||||
| River Lethe | runs through | House of Sleep | House of Sleep | runs_through | river Lethe | |
| ivory gate | issues | deceptive dreams | ivory gate | issues | deceptive dreams | |
| horn gate | issues | true dreams | horn gate | issues | true dreams | |
| House of Sleep | contains | two gates | House of Sleep | has_gate | ivory gate | |
| House of Sleep | has_gate | horn gate | ||||
| 11G311 (Michael resting beside the dragon’s corpse) | ||||||
| Michael | rests beside | dragon’s corpse | Michael | resting_beside | dragon’s corpse | |
| Dragon | represented as | corpse | ||||
| 11U4 (Mary and John the Baptist together with (e.g. kneeling before) the judging Christ, ’Deesis’ Last Judgement) | ||||||
| Mary | kneels before | Christ | Mary | kneels_before | judging Christ | |
| John the Baptist | kneels before | Christ | John the Baptist | kneels_before | judging Christ | |
| Mary | together with | John the Baptist | ||||
| Christ | represented as | Judge | ||||
| 29B (Plants behaving as human beings or animals) | ||||||
| plants | behave like | human beings | plants | behaving_as | human beings | |
| plants | behave like | animals | plants | behaving_as | animals | |
| 94P68 ((story of) Perseus – death) | ||||||
| Perseus | kills | Medusa | ||||

Figure 2
Search results in iART for the queries “Amor” (a) and “Pietà” (b), with the facets “time start” and “location” expanded.

Figure 3
Search results in iART for the queries “wisdom” (a) and “beauty” (b), with the facets “time start” and “depicts” expanded.

Figure 4
Search results in iART for the queries “warrior” (a) and “market” (b), with the facets “time start” and “material” expanded.

Figure 5
Search results in iART for the queries “nude” (a) and “naked” (b), with the facets “time start” and “depicts” expanded.
