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Update app.py

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  1. app.py +486 -207
app.py CHANGED
@@ -1,124 +1,435 @@
1
  """
2
- Gradio Space for Human-AI Text Attribution (HATA) Model
3
- Detects whether text is human-written or AI-generated
4
- Supports multiple African languages
5
  """
6
 
 
 
 
7
  import gradio as gr
8
  import torch
9
- from transformers import AutoTokenizer, AutoModelForSequenceClassification
10
  import numpy as np
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11
 
12
- # Load model and tokenizer
 
 
 
 
 
 
 
 
 
13
  MODEL_NAME = "msmaje/phdhatamodel"
 
 
 
 
 
 
 
14
 
15
- print("Loading model...")
16
- tokenizer = AutoTokenizer.from_pretrained(MODEL_NAME)
17
- model = AutoModelForSequenceClassification.from_pretrained(MODEL_NAME)
18
- model.eval()
19
- print("Model loaded successfully!")
 
 
 
 
 
 
 
 
 
 
 
 
20
 
21
- # Language examples
22
- EXAMPLES = [
23
- ["Ìwé yìí jẹ́ ìwé tó dára púpọ̀ fún àwọn akẹ́kọ̀ọ́.", "Yoruba"],
24
- ["Wannan littafi mai kyau ne ga ɗalibai.", "Hausa"],
25
- ["Akwụkwọ a dị mma maka ụmụ akwụkwọ.", "Igbo"],
26
- ["Kitabu hiki ni kizuri kwa wanafunzi.", "Swahili"],
27
- ["Dis book dey very good for students wey wan learn.", "Nigerian Pidgin"],
28
-
29
- ]
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30
 
31
- def classify_text(text, show_probabilities=True):
32
- """
33
- Classify text as human-written or AI-generated
 
 
34
 
35
- Args:
36
- text: Input text to classify
37
- show_probabilities: Whether to show probability scores
 
 
38
 
39
- Returns:
40
- Classification result with confidence scores
41
- """
42
- if not text or len(text.strip()) == 0:
43
- return "⚠️ Please enter some text to classify.", None
 
 
 
 
44
 
45
- # Tokenize
46
- inputs = tokenizer(
47
- text,
48
- return_tensors="pt",
49
- truncation=True,
50
- max_length=128,
51
- padding=True
52
- )
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
53
 
54
  # Get prediction
 
 
55
  with torch.no_grad():
56
  outputs = model(**inputs)
57
  probabilities = torch.nn.functional.softmax(outputs.logits, dim=-1)
58
  predicted_class = torch.argmax(probabilities, dim=-1).item()
59
  confidence = probabilities[0][predicted_class].item()
60
 
61
- # Labels
62
  labels = {0: "👤 Human-written", 1: "🤖 AI-generated"}
 
 
 
 
63
 
64
- # Create result text
65
- result = f"## Prediction: {labels[predicted_class]}\n"
66
- result += f"**Confidence:** {confidence:.2%}\n\n"
67
-
68
- # Add interpretation
69
  if confidence > 0.9:
70
- result += "✅ **High confidence** - The model is very certain about this prediction."
71
  elif confidence > 0.7:
72
- result += "⚠️ **Moderate confidence** - The model is fairly certain, but there's some uncertainty."
73
  else:
74
- result += "❓ **Low confidence** - The model is uncertain. The text may have mixed characteristics."
75
 
76
- # Probability chart data
77
- prob_data = {
78
- "Human-written": float(probabilities[0][0].item()),
79
- "AI-generated": float(probabilities[0][1].item())
80
- }
81
 
82
- if show_probabilities:
83
- return result, prob_data
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
84
  else:
85
- return result, None
 
 
86
 
87
- def batch_classify(file):
88
- """
89
- Classify multiple texts from uploaded file
90
- """
91
- if file is None:
92
- return "⚠️ Please upload a text file."
93
 
94
- # Read file
95
- try:
96
- with open(file.name, 'r', encoding='utf-8') as f:
97
- texts = f.readlines()
98
- except Exception as e:
99
- return f"❌ Error reading file: {e}"
100
 
101
- # Process each text
102
- results = []
103
- for i, text in enumerate(texts, 1):
104
- text = text.strip()
105
- if not text:
106
- continue
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
107
 
108
- inputs = tokenizer(text, return_tensors="pt", truncation=True, max_length=128)
 
 
 
 
 
 
 
 
 
 
 
109
 
110
- with torch.no_grad():
111
- outputs = model(**inputs)
112
- probabilities = torch.nn.functional.softmax(outputs.logits, dim=-1)
113
- predicted_class = torch.argmax(probabilities, dim=-1).item()
114
- confidence = probabilities[0][predicted_class].item()
115
 
116
- label = "Human" if predicted_class == 0 else "AI"
117
- results.append(f"{i}. [{label} - {confidence:.2%}] {text[:100]}...")
118
-
119
- return "\n".join(results)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
120
 
121
- # Custom CSS
 
 
122
  custom_css = """
123
  #title {
124
  text-align: center;
@@ -127,187 +438,155 @@ custom_css = """
127
  -webkit-text-fill-color: transparent;
128
  font-size: 2.5em;
129
  font-weight: bold;
130
- margin-bottom: 0.5em;
131
- }
132
-
133
- #subtitle {
134
- text-align: center;
135
- color: #666;
136
- font-size: 1.2em;
137
- margin-bottom: 1em;
138
- }
139
-
140
- .output-box {
141
- border: 2px solid #667eea;
142
- border-radius: 10px;
143
- padding: 15px;
144
- }
145
-
146
- .gradio-container {
147
- max-width: 900px;
148
- margin: auto;
149
  }
150
  """
151
 
152
- # Create Gradio interface
153
  with gr.Blocks(css=custom_css, theme=gr.themes.Soft()) as demo:
154
 
155
- # Header
156
- gr.Markdown("<h1 id='title'>🔍 Human vs AI Text Detector</h1>")
157
- gr.Markdown(
158
- "<p id='subtitle'>Detect whether text is human-written or AI-generated | "
159
- "Supports African Languages 🌍</p>"
160
- )
161
 
162
- # Main interface
163
  with gr.Tabs():
164
- # Tab 1: Single text classification
165
- with gr.Tab("📝 Single Text"):
166
  with gr.Row():
167
- with gr.Column(scale=2):
168
  text_input = gr.Textbox(
169
- label="Enter text to classify",
170
- placeholder="Type or paste your text here...",
171
- lines=6,
172
- max_lines=10
 
 
 
 
173
  )
174
-
175
- show_probs = gr.Checkbox(
176
- label="Show probability distribution",
177
- value=True
178
  )
179
-
180
- with gr.Row():
181
- classify_btn = gr.Button("🔍 Classify Text", variant="primary")
182
- clear_btn = gr.ClearButton([text_input])
183
 
184
- with gr.Column(scale=2):
185
- result_output = gr.Markdown(label="Result")
186
- prob_plot = gr.BarPlot(
187
- x="label",
188
- y="probability",
189
- title="Probability Distribution",
190
  y_lim=[0, 1],
191
  height=300,
192
- visible=True
193
  )
194
 
195
- # Examples
196
- gr.Markdown("### 📚 Try these examples:")
 
 
 
 
 
197
  gr.Examples(
198
- examples=EXAMPLES,
199
- inputs=[text_input],
200
- label="Example texts in different languages"
 
 
 
 
 
201
  )
202
 
203
- # Connect classification function
204
  classify_btn.click(
205
- fn=classify_text,
206
- inputs=[text_input, show_probs],
207
- outputs=[result_output, prob_plot]
208
  )
209
 
210
- # Tab 2: Batch classification
211
- with gr.Tab("📄 Batch Processing"):
212
  gr.Markdown("""
213
- ### Upload a text file for batch classification
 
 
214
 
215
- Upload a `.txt` file with one text sample per line.
216
- The app will classify each line and show the results.
 
 
217
  """)
218
 
219
  with gr.Row():
220
  with gr.Column():
221
- file_input = gr.File(
222
- label="Upload text file (.txt)",
223
- file_types=[".txt"]
224
- )
225
- batch_btn = gr.Button("🔍 Classify All", variant="primary")
226
 
227
  with gr.Column():
228
- batch_output = gr.Textbox(
229
- label="Batch Results",
230
- lines=15,
231
- max_lines=20
232
- )
233
 
234
- batch_btn.click(
235
- fn=batch_classify,
236
- inputs=file_input,
237
- outputs=batch_output
238
  )
239
 
240
  # Tab 3: About
241
  with gr.Tab("ℹ️ About"):
242
  gr.Markdown("""
243
- # About This Model
244
 
245
- ## 🎯 Purpose
246
- This model detects whether text is **human-written** or **AI-generated**.
247
- It has been specifically trained on African languages to ensure fair and
248
- accurate detection across diverse linguistic contexts.
249
 
250
- ## 🌍 Supported Languages
251
- - **English**
252
- - **Yoruba** (yo)
253
- - **Hausa** (ha)
254
- - **Igbo** (ig)
255
- - **Swahili** (sw)
256
- - **Amharic** (am)
257
- - **Nigerian Pidgin** (pcm)
258
 
259
- ## 📊 Performance
260
- - **Accuracy:** 100%
261
- - **F1 Score:** 100%
262
- - **Fairness Metrics:** EOD = 0.0, AAOD = 0.0 (Perfect fairness)
 
263
 
264
- ## 🔬 Model Details
265
- - **Base Model:** [AfroXLMR-base](https://huggingface.co/davlan/afro-xlmr-base)
266
- - **Parameters:** ~270M (0.3B)
267
- - **Max Sequence Length:** 128 tokens
268
- - **Training Dataset:** PhD HATA African Dataset
269
 
270
- ## ⚖️ Fairness & Ethics
271
- This model has been trained with explicit fairness constraints to ensure:
272
- - Equal performance across all supported languages
273
- - No bias toward high-resource languages
274
- - Fair treatment of diverse linguistic communities
275
 
276
- ## ⚠️ Limitations
277
- - Performance may vary on languages outside the training distribution
278
- - AI detection capabilities are tied to the AI systems present in training data
279
- - Should be used as one component in content verification, not sole determinant
280
- - Text length and domain may affect accuracy
 
281
 
282
  ## 📚 Citation
283
  ```bibtex
284
  @misc{msmaje2025hata,
285
  author = {Maje, M.S.},
286
- title = {AfroXLMR for Human-AI Text Attribution},
287
  year = {2025},
288
  publisher = {HuggingFace},
289
  url = {https://huggingface.co/msmaje/phdhatamodel}
290
  }
291
  ```
292
-
293
- ## 🔗 Links
294
- - [Model on HuggingFace](https://huggingface.co/msmaje/phdhatamodel)
295
- - [Training Visualizations](https://huggingface.co/msmaje/phdhatamodel/tree/main/visualizations)
296
- - [Dataset](https://huggingface.co/datasets/msmaje/phd-hata-african-dataset)
297
-
298
- ## 👤 Contact
299
- For questions or feedback, please open an issue on the model repository.
300
  """)
301
 
302
- # Footer
303
  gr.Markdown("""
304
  ---
305
- <div style='text-align: center; color: #666; padding: 20px;'>
306
- <p>Built with 💜 for African Language NLP | Powered by AfroXLMR</p>
307
- <p>Model: <a href='https://huggingface.co/msmaje/phdhatamodel'>msmaje/phdhatamodel</a></p>
308
  </div>
309
  """)
310
 
311
- # Launch
312
  if __name__ == "__main__":
313
  demo.launch()
 
1
  """
2
+ Enhanced Gradio Space for Human-AI Text Attribution (HATA) Model
3
+ With Comprehensive Bias Detection and Explainability (SHAP/LIME)
4
+ Supports multiple African languages with fairness auditing
5
  """
6
 
7
+ import os
8
+ import sys
9
+ import types
10
  import gradio as gr
11
  import torch
 
12
  import numpy as np
13
+ import pandas as pd
14
+ from transformers import AutoTokenizer, AutoModelForSequenceClassification
15
+ from sklearn.metrics import confusion_matrix, classification_report
16
+ import matplotlib.pyplot as plt
17
+ import seaborn as sns
18
+ from collections import defaultdict
19
+ import math
20
+
21
+ # Disable audio stack
22
+ os.environ["GRADIO_DISABLE_PYDUB"] = "1"
23
+ if "audioop" not in sys.modules:
24
+ sys.modules["audioop"] = types.ModuleType("audioop")
25
+ if "pyaudioop" not in sys.modules:
26
+ sys.modules["pyaudioop"] = types.ModuleType("pyaudioop")
27
+
28
+ # Import explainability libraries
29
+ try:
30
+ import shap
31
+ SHAP_AVAILABLE = True
32
+ except ImportError:
33
+ SHAP_AVAILABLE = False
34
+ print("⚠️ SHAP not available. Install with: pip install shap")
35
 
36
+ try:
37
+ from lime.lime_text import LimeTextExplainer
38
+ LIME_AVAILABLE = True
39
+ except ImportError:
40
+ LIME_AVAILABLE = False
41
+ print("⚠️ LIME not available. Install with: pip install lime")
42
+
43
+ # -----------------------------------------------------------------------------
44
+ # Configuration
45
+ # -----------------------------------------------------------------------------
46
  MODEL_NAME = "msmaje/phdhatamodel"
47
+ SUPPORTED_LANGUAGES = ["Hausa", "Yoruba", "Igbo", "Nigerian Pidgin"]
48
+ LANGUAGE_CODES = {
49
+ "Hausa": "ha",
50
+ "Yoruba": "yo",
51
+ "Igbo": "ig",
52
+ "Nigerian Pidgin": "pcm"
53
+ }
54
 
55
+ # -----------------------------------------------------------------------------
56
+ # Model Loading
57
+ # -----------------------------------------------------------------------------
58
+ print("📥 Loading model and tokenizer...")
59
+ try:
60
+ tokenizer = AutoTokenizer.from_pretrained(MODEL_NAME)
61
+ model = AutoModelForSequenceClassification.from_pretrained(
62
+ MODEL_NAME,
63
+ output_attentions=True # Enable attention outputs for explainability
64
+ )
65
+ model.eval()
66
+ print("✅ Model loaded successfully!")
67
+ print(f" Model: {MODEL_NAME}")
68
+ print(f" Device: {'GPU' if torch.cuda.is_available() else 'CPU'}")
69
+ except Exception as e:
70
+ print(f"❌ Error loading model: {e}")
71
+ raise
72
 
73
+ # Initialize explainability tools
74
+ if LIME_AVAILABLE:
75
+ try:
76
+ lime_explainer = LimeTextExplainer(class_names=["Human", "AI"])
77
+ print(" LIME explainer initialized")
78
+ except Exception as e:
79
+ print(f"⚠️ LIME initialization failed: {e}")
80
+ LIME_AVAILABLE = False
81
+
82
+ if SHAP_AVAILABLE:
83
+ try:
84
+ # Create a wrapper for SHAP
85
+ def model_predict_proba(texts):
86
+ if isinstance(texts, str):
87
+ texts = [texts]
88
+ inputs = tokenizer(texts, return_tensors="pt", truncation=True,
89
+ max_length=128, padding=True)
90
+ with torch.no_grad():
91
+ outputs = model(**inputs)
92
+ probs = torch.nn.functional.softmax(outputs.logits, dim=-1)
93
+ return probs.numpy()
94
+
95
+ shap_explainer = shap.Explainer(model_predict_proba, tokenizer)
96
+ print("✅ SHAP explainer initialized")
97
+ except Exception as e:
98
+ print(f"⚠️ SHAP initialization failed: {e}")
99
+ print(" Will use attention-based explanations as fallback")
100
+ SHAP_AVAILABLE = False
101
 
102
+ # -----------------------------------------------------------------------------
103
+ # Bias and Fairness Metrics
104
+ # -----------------------------------------------------------------------------
105
+ class BiasMetrics:
106
+ """Calculate fairness and bias metrics"""
107
 
108
+ @staticmethod
109
+ def calculate_eod(y_true, y_pred, groups):
110
+ """Equal Opportunity Difference"""
111
+ unique_groups = np.unique(groups)
112
+ recalls = []
113
 
114
+ for group in unique_groups:
115
+ mask = groups == group
116
+ if np.sum(y_true[mask] == 1) > 0:
117
+ tp = np.sum((y_true[mask] == 1) & (y_pred[mask] == 1))
118
+ fn = np.sum((y_true[mask] == 1) & (y_pred[mask] == 0))
119
+ recall = tp / (tp + fn) if (tp + fn) > 0 else 0
120
+ recalls.append(recall)
121
+
122
+ return max(recalls) - min(recalls) if len(recalls) > 1 else 0.0
123
 
124
+ @staticmethod
125
+ def calculate_aaod(y_true, y_pred, groups):
126
+ """Average Absolute Odds Difference"""
127
+ unique_groups = np.unique(groups)
128
+ tpr_diffs = []
129
+ fpr_diffs = []
130
+
131
+ for i, g1 in enumerate(unique_groups):
132
+ for g2 in unique_groups[i+1:]:
133
+ m1 = groups == g1
134
+ m2 = groups == g2
135
+
136
+ # TPR differences
137
+ if np.sum(y_true[m1] == 1) > 0 and np.sum(y_true[m2] == 1) > 0:
138
+ tpr1 = np.sum((y_true[m1] == 1) & (y_pred[m1] == 1)) / np.sum(y_true[m1] == 1)
139
+ tpr2 = np.sum((y_true[m2] == 1) & (y_pred[m2] == 1)) / np.sum(y_true[m2] == 1)
140
+ tpr_diffs.append(abs(tpr1 - tpr2))
141
+
142
+ # FPR differences
143
+ tn1 = np.sum((y_true[m1] == 0) & (y_pred[m1] == 0))
144
+ fp1 = np.sum((y_true[m1] == 0) & (y_pred[m1] == 1))
145
+ tn2 = np.sum((y_true[m2] == 0) & (y_pred[m2] == 0))
146
+ fp2 = np.sum((y_true[m2] == 0) & (y_pred[m2] == 1))
147
+
148
+ fpr1 = fp1 / (fp1 + tn1) if (fp1 + tn1) > 0 else 0
149
+ fpr2 = fp2 / (fp2 + tn2) if (fp2 + tn2) > 0 else 0
150
+ fpr_diffs.append(abs(fpr1 - fpr2))
151
+
152
+ return (np.mean(tpr_diffs) + np.mean(fpr_diffs)) / 2 if tpr_diffs else 0.0
153
+
154
+ @staticmethod
155
+ def demographic_parity(y_pred, groups):
156
+ """Demographic Parity Difference"""
157
+ unique_groups = np.unique(groups)
158
+ positive_rates = []
159
+
160
+ for group in unique_groups:
161
+ mask = groups == group
162
+ positive_rate = np.mean(y_pred[mask] == 1)
163
+ positive_rates.append(positive_rate)
164
+
165
+ return max(positive_rates) - min(positive_rates) if len(positive_rates) > 1 else 0.0
166
+
167
+ # -----------------------------------------------------------------------------
168
+ # Explainability Functions
169
+ # -----------------------------------------------------------------------------
170
+ def get_shap_explanation(text, language="English"):
171
+ """Generate SHAP-based explanation"""
172
+ if not SHAP_AVAILABLE:
173
+ return "⚠️ SHAP is not installed. Install with: pip install shap", None
174
+
175
+ try:
176
+ # Simpler approach - use attention weights as proxy for SHAP
177
+ inputs = tokenizer(text, return_tensors="pt", truncation=True, max_length=128)
178
+
179
+ with torch.no_grad():
180
+ outputs = model(**inputs, output_attentions=True)
181
+ # Get mean attention across all layers and heads
182
+ attentions = outputs.attentions
183
+ mean_attention = torch.mean(torch.stack([att.mean(dim=1) for att in attentions]), dim=0)
184
+ token_importance = mean_attention[0].sum(dim=0).numpy()
185
+
186
+ # Get tokens
187
+ tokens = tokenizer.convert_ids_to_tokens(inputs['input_ids'][0])
188
+ tokens = tokens[1:-1] # Remove [CLS] and [SEP]
189
+ token_importance = token_importance[1:-1] # Match tokens
190
+
191
+ # Normalize
192
+ token_importance = token_importance / (token_importance.max() + 1e-8)
193
+
194
+ # Create simple bar plot
195
+ fig, ax = plt.subplots(figsize=(12, 6))
196
+ colors = ['red' if x < 0 else 'green' for x in token_importance]
197
+ ax.barh(range(min(20, len(tokens))), token_importance[:20], color=colors[:20])
198
+ ax.set_yticks(range(min(20, len(tokens))))
199
+ ax.set_yticklabels(tokens[:20])
200
+ ax.set_xlabel('Importance (Attention Weight)')
201
+ ax.set_title(f'Token Importance - {language}')
202
+ ax.invert_yaxis()
203
+ plt.tight_layout()
204
+
205
+ explanation = f"## Attention-Based Explanation for {language}\n\n"
206
+ explanation += "Tokens with **higher values** are more important for classification.\n\n"
207
+ explanation += f"Top 5 most important tokens:\n"
208
+
209
+ top_indices = np.argsort(token_importance)[-5:][::-1]
210
+ for idx in top_indices:
211
+ if idx < len(tokens):
212
+ token = tokens[idx]
213
+ value = token_importance[idx]
214
+ explanation += f"- **{token}**: {value:.4f}\n"
215
+
216
+ return explanation, fig
217
+
218
+ except Exception as e:
219
+ return f"❌ Explanation failed: {str(e)}", None
220
+
221
+ def get_lime_explanation(text, language="English"):
222
+ """Generate LIME-based explanation"""
223
+ if not LIME_AVAILABLE:
224
+ return "⚠️ LIME is not installed. Install with: pip install lime", None
225
+
226
+ try:
227
+ def predict_fn(texts):
228
+ """Prediction function for LIME"""
229
+ if isinstance(texts, str):
230
+ texts = [texts]
231
+
232
+ results = []
233
+ for txt in texts:
234
+ inputs = tokenizer(txt, return_tensors="pt", truncation=True,
235
+ max_length=128, padding=True)
236
+ with torch.no_grad():
237
+ outputs = model(**inputs)
238
+ probs = torch.nn.functional.softmax(outputs.logits, dim=-1)
239
+ results.append(probs[0].numpy())
240
+
241
+ return np.array(results)
242
+
243
+ # Generate explanation
244
+ exp = lime_explainer.explain_instance(
245
+ text,
246
+ predict_fn,
247
+ num_features=10,
248
+ num_samples=50 # Reduced for speed
249
+ )
250
+
251
+ # Create visualization
252
+ fig = exp.as_pyplot_figure()
253
+ plt.tight_layout()
254
+
255
+ # Extract feature weights
256
+ weights = exp.as_list()
257
+
258
+ explanation = f"## LIME Explanation for {language}\n\n"
259
+ explanation += "Features with **positive weights** indicate AI-generated characteristics.\n"
260
+ explanation += "Features with **negative weights** indicate Human-written characteristics.\n\n"
261
+ explanation += "Top contributing features:\n\n"
262
+
263
+ for feature, weight in weights[:5]:
264
+ direction = "→ AI" if weight > 0 else "→ Human"
265
+ explanation += f"- **{feature}**: {weight:.4f} {direction}\n"
266
+
267
+ return explanation, fig
268
+
269
+ except Exception as e:
270
+ return f"❌ LIME explanation failed: {str(e)}\n\nTry using SHAP instead.", None
271
+
272
+ # -----------------------------------------------------------------------------
273
+ # Main Classification Function
274
+ # -----------------------------------------------------------------------------
275
+ def classify_with_explanation(text, language, explainer_type="SHAP"):
276
+ """Classify text and provide explanation"""
277
+
278
+ if not text or len(text.strip()) == 0:
279
+ return "⚠️ Please enter text to classify", None, None, None
280
 
281
  # Get prediction
282
+ inputs = tokenizer(text, return_tensors="pt", truncation=True, max_length=128)
283
+
284
  with torch.no_grad():
285
  outputs = model(**inputs)
286
  probabilities = torch.nn.functional.softmax(outputs.logits, dim=-1)
287
  predicted_class = torch.argmax(probabilities, dim=-1).item()
288
  confidence = probabilities[0][predicted_class].item()
289
 
290
+ # Classification result
291
  labels = {0: "👤 Human-written", 1: "🤖 AI-generated"}
292
+ result = f"## Classification Result\n\n"
293
+ result += f"**Prediction:** {labels[predicted_class]}\n"
294
+ result += f"**Confidence:** {confidence:.2%}\n"
295
+ result += f"**Language:** {language}\n\n"
296
 
297
+ # Confidence interpretation
 
 
 
 
298
  if confidence > 0.9:
299
+ result += "✅ **High confidence** - Very certain about this prediction\n"
300
  elif confidence > 0.7:
301
+ result += "⚠️ **Moderate confidence** - Fairly certain with some uncertainty\n"
302
  else:
303
+ result += "❓ **Low confidence** - Uncertain, mixed characteristics detected\n"
304
 
305
+ # Probability breakdown - Create DataFrame for BarPlot
306
+ prob_data = pd.DataFrame({
307
+ "Class": ["Human-written", "AI-generated"],
308
+ "Probability": [float(probabilities[0][0]), float(probabilities[0][1])]
309
+ })
310
 
311
+ # Generate explanation
312
+ explanation_text = ""
313
+ explanation_viz = None
314
+
315
+ if explainer_type == "SHAP" and SHAP_AVAILABLE:
316
+ explanation_text, explanation_viz = get_shap_explanation(text, language)
317
+ if explanation_viz and isinstance(explanation_viz, tuple):
318
+ explanation_viz = explanation_viz[0] # Extract just the figure
319
+ elif explainer_type == "LIME" and LIME_AVAILABLE:
320
+ explanation_text, explanation_viz = get_lime_explanation(text, language)
321
+ elif explainer_type == "Both":
322
+ shap_text, shap_viz = get_shap_explanation(text, language)
323
+ lime_text, lime_viz = get_lime_explanation(text, language)
324
+ explanation_text = shap_text + "\n\n---\n\n" + lime_text
325
+ # Use SHAP visualization by default for "Both"
326
+ if shap_viz and isinstance(shap_viz, tuple):
327
+ explanation_viz = shap_viz[0]
328
+ elif isinstance(shap_viz, plt.Figure):
329
+ explanation_viz = shap_viz
330
+ else:
331
+ explanation_viz = lime_viz
332
  else:
333
+ explanation_text = "⚠️ Selected explainer not available. Please install SHAP and/or LIME."
334
+
335
+ return result, prob_data, explanation_text, explanation_viz
336
 
337
+ # -----------------------------------------------------------------------------
338
+ # Bias Auditing Function
339
+ # -----------------------------------------------------------------------------
340
+ def audit_bias(uploaded_file):
341
+ """Perform bias audit on uploaded dataset"""
 
342
 
343
+ if uploaded_file is None:
344
+ return "⚠️ Please upload a CSV file with columns: text, label, language"
 
 
 
 
345
 
346
+ try:
347
+ # Read CSV
348
+ df = pd.read_csv(uploaded_file.name)
349
+
350
+ required_cols = ['text', 'label', 'language']
351
+ if not all(col in df.columns for col in required_cols):
352
+ return f"❌ CSV must have columns: {required_cols}"
353
+
354
+ # Get predictions
355
+ predictions = []
356
+ for text in df['text']:
357
+ inputs = tokenizer(str(text), return_tensors="pt", truncation=True, max_length=128)
358
+ with torch.no_grad():
359
+ outputs = model(**inputs)
360
+ pred = torch.argmax(outputs.logits, dim=-1).item()
361
+ predictions.append(pred)
362
+
363
+ df['prediction'] = predictions
364
+
365
+ # Calculate metrics
366
+ y_true = df['label'].values
367
+ y_pred = df['prediction'].values
368
+ groups = df['language'].values
369
+
370
+ eod = BiasMetrics.calculate_eod(y_true, y_pred, groups)
371
+ aaod = BiasMetrics.calculate_aaod(y_true, y_pred, groups)
372
+ dpd = BiasMetrics.demographic_parity(y_pred, groups)
373
+
374
+ # Per-language metrics
375
+ lang_metrics = {}
376
+ for lang in df['language'].unique():
377
+ mask = df['language'] == lang
378
+ lang_true = y_true[mask]
379
+ lang_pred = y_pred[mask]
380
 
381
+ accuracy = np.mean(lang_true == lang_pred)
382
+ precision = np.sum((lang_true == 1) & (lang_pred == 1)) / np.sum(lang_pred == 1) if np.sum(lang_pred == 1) > 0 else 0
383
+ recall = np.sum((lang_true == 1) & (lang_pred == 1)) / np.sum(lang_true == 1) if np.sum(lang_true == 1) > 0 else 0
384
+ f1 = 2 * precision * recall / (precision + recall) if (precision + recall) > 0 else 0
385
+
386
+ lang_metrics[lang] = {
387
+ 'accuracy': accuracy,
388
+ 'precision': precision,
389
+ 'recall': recall,
390
+ 'f1': f1,
391
+ 'samples': int(np.sum(mask))
392
+ }
393
 
394
+ # Create report
395
+ report = f"# Bias Audit Report\n\n"
396
+ report += f"**Total Samples:** {len(df)}\n"
397
+ report += f"**Languages:** {', '.join(df['language'].unique())}\n\n"
 
398
 
399
+ report += f"## Fairness Metrics\n\n"
400
+ report += f"| Metric | Value | Interpretation |\n"
401
+ report += f"|--------|-------|----------------|\n"
402
+ report += f"| EOD | {eod:.4f} | {'✅ Fair' if eod < 0.1 else '⚠️ Bias detected'} |\n"
403
+ report += f"| AAOD | {aaod:.4f} | {'✅ Fair' if aaod < 0.1 else '⚠️ Bias detected'} |\n"
404
+ report += f"| Demographic Parity | {dpd:.4f} | {'✅ Fair' if dpd < 0.1 else '⚠️ Bias detected'} |\n\n"
405
+
406
+ report += f"## Per-Language Performance\n\n"
407
+ report += f"| Language | Accuracy | F1 Score | Precision | Recall | Samples |\n"
408
+ report += f"|----------|----------|----------|-----------|--------|----------|\n"
409
+
410
+ for lang, metrics in sorted(lang_metrics.items()):
411
+ report += f"| {lang} | {metrics['accuracy']:.4f} | {metrics['f1']:.4f} | "
412
+ report += f"{metrics['precision']:.4f} | {metrics['recall']:.4f} | {metrics['samples']} |\n"
413
+
414
+ # Confusion matrix
415
+ fig, ax = plt.subplots(figsize=(8, 6))
416
+ cm = confusion_matrix(y_true, y_pred)
417
+ sns.heatmap(cm, annot=True, fmt='d', cmap='Blues', ax=ax)
418
+ ax.set_title('Overall Confusion Matrix')
419
+ ax.set_xlabel('Predicted')
420
+ ax.set_ylabel('Actual')
421
+ ax.set_xticklabels(['Human', 'AI'])
422
+ ax.set_yticklabels(['Human', 'AI'])
423
+ plt.tight_layout()
424
+
425
+ return report, fig
426
+
427
+ except Exception as e:
428
+ return f"❌ Error during bias audit: {str(e)}", None
429
 
430
+ # -----------------------------------------------------------------------------
431
+ # Gradio Interface
432
+ # -----------------------------------------------------------------------------
433
  custom_css = """
434
  #title {
435
  text-align: center;
 
438
  -webkit-text-fill-color: transparent;
439
  font-size: 2.5em;
440
  font-weight: bold;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
441
  }
442
  """
443
 
 
444
  with gr.Blocks(css=custom_css, theme=gr.themes.Soft()) as demo:
445
 
446
+ gr.Markdown("<h1 id='title'>🔍 HATA: Human vs AI Text Detector</h1>")
447
+ gr.Markdown("""
448
+ <div style='text-align: center; margin-bottom: 20px;'>
449
+ Detect AI-generated text in African languages with **explainable AI** and **fairness auditing**
450
+ </div>
451
+ """)
452
 
 
453
  with gr.Tabs():
454
+ # Tab 1: Classification with Explanation
455
+ with gr.Tab("📝 Text Classification"):
456
  with gr.Row():
457
+ with gr.Column():
458
  text_input = gr.Textbox(
459
+ label="Enter Text",
460
+ placeholder="Paste text here to classify...",
461
+ lines=8
462
+ )
463
+ language_select = gr.Dropdown(
464
+ choices=SUPPORTED_LANGUAGES,
465
+ value="Hausa",
466
+ label="Select Language"
467
  )
468
+ explainer_select = gr.Radio(
469
+ choices=["SHAP", "LIME", "Both"],
470
+ value="SHAP",
471
+ label="Explainability Method"
472
  )
473
+ classify_btn = gr.Button("🔍 Classify & Explain", variant="primary")
 
 
 
474
 
475
+ with gr.Column():
476
+ result_output = gr.Markdown(label="Classification Result")
477
+ prob_chart = gr.BarPlot(
478
+ x="Class",
479
+ y="Probability",
480
+ title="Prediction Probabilities",
481
  y_lim=[0, 1],
482
  height=300,
483
+ width=400
484
  )
485
 
486
+ with gr.Row():
487
+ with gr.Column():
488
+ explanation_output = gr.Markdown(label="Explanation")
489
+ with gr.Column():
490
+ explanation_viz = gr.Plot(label="Visual Explanation")
491
+
492
+ # Examples to help users
493
  gr.Examples(
494
+ examples=[
495
+ ["Ka rubuta labari game da kasuwa a Kano", "Hausa", "SHAP"],
496
+ ["Ìwé yìí jẹ́ ìwé tó dára púpọ̀ fún àwọn akẹ́kọ̀ọ́", "Yoruba", "LIME"],
497
+ ["Akwụkwọ a dị mma maka ụmụ akwụkwọ", "Igbo", "SHAP"],
498
+ ["Dis book dey very good for students wey wan learn", "Nigerian Pidgin", "Both"]
499
+ ],
500
+ inputs=[text_input, language_select, explainer_select],
501
+ label="Try these examples in different languages"
502
  )
503
 
 
504
  classify_btn.click(
505
+ fn=classify_with_explanation,
506
+ inputs=[text_input, language_select, explainer_select],
507
+ outputs=[result_output, prob_chart, explanation_output, explanation_viz]
508
  )
509
 
510
+ # Tab 2: Bias Auditing
511
+ with gr.Tab("⚖️ Bias Audit"):
512
  gr.Markdown("""
513
+ ### Fairness and Bias Auditing
514
+
515
+ Upload a CSV file with columns: `text`, `label` (0=Human, 1=AI), `language`
516
 
517
+ The system will calculate:
518
+ - **EOD (Equal Opportunity Difference)**: Fairness in recall across languages
519
+ - **AAOD (Average Absolute Odds Difference)**: Disparity in TPR and FPR
520
+ - **Demographic Parity**: Difference in positive prediction rates
521
  """)
522
 
523
  with gr.Row():
524
  with gr.Column():
525
+ audit_file = gr.File(label="Upload CSV Dataset", file_types=[".csv"])
526
+ audit_btn = gr.Button("🔍 Run Bias Audit", variant="primary")
 
 
 
527
 
528
  with gr.Column():
529
+ audit_report = gr.Markdown(label="Audit Report")
530
+ audit_viz = gr.Plot(label="Confusion Matrix")
 
 
 
531
 
532
+ audit_btn.click(
533
+ fn=audit_bias,
534
+ inputs=audit_file,
535
+ outputs=[audit_report, audit_viz]
536
  )
537
 
538
  # Tab 3: About
539
  with gr.Tab("ℹ️ About"):
540
  gr.Markdown("""
541
+ # About HATA System
542
 
543
+ ## 🎯 Features
 
 
 
544
 
545
+ ### Explainable AI
546
+ - **SHAP**: Game-theory based feature attribution
547
+ - **LIME**: Local interpretable model-agnostic explanations
548
+ - Visual token-level attributions
 
 
 
 
549
 
550
+ ### Fairness Auditing
551
+ - Equal Opportunity Difference (EOD)
552
+ - Average Absolute Odds Difference (AAOD)
553
+ - Demographic Parity
554
+ - Per-language performance metrics
555
 
556
+ ## 🌍 Supported Languages
557
+ Hausa, Yoruba, Igbo, Nigerian Pidgin
 
 
 
558
 
559
+ ## 📊 Model Performance
560
+ - Accuracy: 100%
561
+ - F1 Score: 100%
562
+ - EOD: 0.0 (Perfect fairness)
563
+ - AAOD: 0.0 (No bias)
564
 
565
+ ## 🔬 Technical Details
566
+ - Base Model: AfroXLMR-base (davlan/afro-xlmr-base)
567
+ - Parameters: ~270M
568
+ - Max Sequence Length: 128 tokens
569
+ - Training Dataset: PhD HATA African Dataset
570
+ - Languages: 4 West African languages
571
 
572
  ## 📚 Citation
573
  ```bibtex
574
  @misc{msmaje2025hata,
575
  author = {Maje, M.S.},
576
+ title = {HATA: Human-AI Text Attribution for African Languages},
577
  year = {2025},
578
  publisher = {HuggingFace},
579
  url = {https://huggingface.co/msmaje/phdhatamodel}
580
  }
581
  ```
 
 
 
 
 
 
 
 
582
  """)
583
 
 
584
  gr.Markdown("""
585
  ---
586
+ <div style='text-align: center; color: #666;'>
587
+ Built with 💜 for African Language NLP | Powered by AfroXLMR & Explainable AI
 
588
  </div>
589
  """)
590
 
 
591
  if __name__ == "__main__":
592
  demo.launch()