Update README.md

README.md

@@ -69,7 +69,7 @@ Each item is composed as follows:
 | `image_path` | Original relative image path from the source dataset. |
 | `query` | The question associated with the document image. |
 | `answer` | The answer associated with the question, stored in list format. |
-| `bbox` | The bounding box of the evidence region, stored in the original nested-list format. Each bounding box is represented as normalized coordinates `[x1, y1, x2, y2]`, where values are in `[0, 1]` relative to the image width and height. |
+| `bbox` | The bounding box of the evidence region, stored in the original nested-list format. Each bounding box is represented as normalized coordinates `[x1, y1, x2, y2]`, where `(x1, y1)` is the top-left corner and `(x2, y2)` is the bottom-right corner. Values are in `[0, 1]` and are relative to the image width and height. |
 | `type` | The semantic type of the evidence region, stored in list format. |
 | `source_dataset` | Name of the source dataset/configuration. |