Fix README: update schema to match actual format (Parquet, JSON-string behavioral fields, empty structs)

README.md

@@ -54,7 +54,9 @@ This dataset has been anonymized:
 
 ## Data Format
 
-The dataset is provided in JSONL format (JSON Lines), where each line is a complete task record.
+The dataset is provided in Parquet format. Each row is a complete task record.
+
+Behavioral trace fields (`rrweb_record`, `event_list`, `mouse_moves`, `page_switch_record`) are stored as JSON strings due to their variable nested structure. All other fields are native types.
 
 ### Schema
 
@@ -63,7 +65,7 @@ The dataset is provided in JSONL format (JSON Lines), where each line is a compl
   "task_id": 1,
   "participant_id": "participant_000001",
   "question": "What is ...",
-  "ground_truth": ["..."],
+  "ground_truth": "...",
   "status": "completed",
   "start_timestamp": "2024-01-15T10:30:00Z",
   "end_timestamp": "2024-01-15T10:45:00Z",
@@ -81,13 +83,21 @@ The dataset is provided in JSONL format (JSON Lines), where each line is a compl
     "familiarity": 2,
     "difficulty": 1,
     "first_search_query": "...",
-    "initial_guess": "..."
+    "initial_guess": "...",
+    "expected_source": ["search_engine"]
   },
   "post_task_annotation": {
     "difficulty_actual": 3,
-    "aha_moment_type": "search_result"
+    "aha_moment_type": "search_result",
+    "strategy_shift": ["..."],
+    "strategy_shift_other": "",
+    "unhelpful_paths": ["..."]
+  },
+  "cancel_annotation": {
+    "category": [],
+    "reason": "",
+    "missing_resource": ""
   },
-  "cancel_annotation": null,
   "trials": [
     {
       "trial_num": 1,
@@ -104,7 +114,7 @@ The dataset is provided in JSONL format (JSON Lines), where each line is a compl
         {
           "url": "https://...",
           "text": "selected text",
-          "dom_position": 150,
+          "dom_position": "CSS selector",
           "relevance": 0.8,
           "credibility": 0.9
         }
@@ -115,9 +125,10 @@ The dataset is provided in JSONL format (JSON Lines), where each line is a compl
           "url": "https://...",
           "referrer": "https://...",
           "dwell_time": 45,
-          "rrweb_record": ["..."],
-          "event_list": ["..."],
-          "mouse_moves": ["..."]
+          "rrweb_record": "[{...}]",
+          "event_list": "[{...}]",
+          "mouse_moves": "[{...}]",
+          "page_switch_record": "[{...}]"
         }
       ]
     }