Update app.py

app.py

@@ -140,8 +140,14 @@ with st.expander("4️⃣ Vocabulary Layer (Vectorization)", expanded=True):
     )
     st.caption("Deletes overly common words (like 'paper' or 'study') that appear everywhere, preventing generic filler from dominating your themes.")
 
-with st.expander("5️⃣ Extraction Layer (Representation)", expanded=True):
-    ui_extraction = st.selectbox("Strategy", ["c-TF-IDF (Word frequency)", "KeyBERTInspired (Semantic cosine)", "MMR (Reduce redundancy)"])
+with st.expander("4️⃣ Extraction Layer (Representation)", expanded=True):
+    st.markdown("*BERTopic ALWAYS extracts baseline words using **c-TF-IDF** (Word Frequency). Do you want to apply an advanced mathematical filter on top of it?*")
+    
+    ui_extraction = st.selectbox(
+        "Apply Advanced Filter:", 
+        ["None (Base c-TF-IDF only)", "KeyBERTInspired (Semantic alignment)", "MMR (Reduce redundancy)"]
+    )
+    
     if "MMR" in ui_extraction:
         mmr_diversity = st.slider("MMR Diversity Penalty", 0.0, 1.0, 0.3)
     else: