\n ## Heatmaps: GPT-2 Name-Copying Heads Analysis ### Overview The image presents two heatmaps comparing "Name-Copying" scores for GPT-2 model heads, one showing the raw score and the other showing a "Suppression" of the score. Both heatmaps visualize the relationship between the layer of the GPT-2 model (x-axis) and the head number (y-axis). The color intensity represents the Name-Copying score, with warmer colors (yellow/green) indicating higher scores and cooler colors (purple) indicating lower scores. Both charts also include scatter plots representing different classifications of heads. ### Components/Axes Both heatmaps share the following components: * **X-axis:** "Layer", ranging from 0 to 11, with tick marks at each integer value. * **Y-axis:** "Head", ranging from 1 to 11, with tick marks at each integer value. * **Color Scale:** A continuous color scale ranging from 0.0 (dark purple) to 1.0 (yellow), representing the "Name Copying score" (left heatmap) and "(Suppression) Name Copying score" (right heatmap). * **Scatter Plot Markers:** * 'Interp. in the Wild' classifications (represented by 'x' markers). * Name-Mover Heads (left heatmap) / (Negative) Name-Mover Heads (right heatmap) (represented by black 'x' markers). * Backup Name-Mover Heads (left heatmap) / Backup (Negative) Name-Mover Heads (right heatmap) (represented by light green circle markers). ### Detailed Analysis or Content Details **Left Heatmap: GPT-2: Name-Copying heads** * **Overall Trend:** The heatmap shows a generally low Name-Copying score across most layers and heads, with a concentration of higher scores (yellow/green) in layers 7-10. * **Data Points (approximate):** * Layer 0-6: Predominantly dark purple, indicating scores near 0.0. * Layer 7: Shows a gradual increase in score, peaking around Head 2-4 at approximately 0.6-0.8. * Layer 8: Similar to Layer 7, with peaks around Head 2-4 at approximately 0.6-0.8. * Layer 9: Peaks around Head 2-4 at approximately 0.8-1.0. * Layer 10: Peaks around Head 2-4 at approximately 0.6-0.8. * Layer 11: Returns to lower scores, around 0.2-0.4. * **Scatter Plot Data:** * 'Interp. in the Wild' classifications: Located at (9, 1), (9, 2), (10, 1), (10, 2), (10, 3), (10, 4), (10, 5), (10, 6), (10, 7), (10, 8), (10, 9), (10, 10), (10, 11). * Name-Mover Heads: Located at (9, 5) with a score of approximately 0.3. * Backup Name-Mover Heads: Located at (8, 2) with a score of approximately 0.7, (9, 2) with a score of approximately 0.8, (10, 2) with a score of approximately 0.6. **Right Heatmap: GPT-2: (Suppression) Name-Copying heads** * **Overall Trend:** This heatmap shows a generally low (Suppression) Name-Copying score across most layers and heads, with a concentration of higher scores (yellow/green) in layers 7-10. * **Data Points (approximate):** * Layer 0-6: Predominantly dark purple, indicating scores near 0.0. * Layer 7: Shows a gradual increase in score, peaking around Head 2-4 at approximately 0.4-0.6. * Layer 8: Similar to Layer 7, with peaks around Head 2-4 at approximately 0.4-0.6. * Layer 9: Peaks around Head 2-4 at approximately 0.6-0.8. * Layer 10: Peaks around Head 2-4 at approximately 0.4-0.6. * Layer 11: Returns to lower scores, around 0.2-0.4. * **Scatter Plot Data:** * 'Interp. in the Wild' classifications: Located at (9, 1), (9, 2), (10, 1), (10, 2), (10, 3), (10, 4), (10, 5), (10, 6), (10, 7), (10, 8), (10, 9), (10, 10), (10, 11). * (Negative) Name-Mover Heads: Located at (9, 5) with a score of approximately 0.3. * Backup (Negative) Name-Mover Heads: Located at (8, 2) with a score of approximately 0.5, (9, 2) with a score of approximately 0.6, (10, 2) with a score of approximately 0.4. ### Key Observations * Both heatmaps exhibit a similar pattern of increased Name-Copying/Suppression scores in layers 7-10, specifically around heads 2-4. * The 'Interp. in the Wild' classifications are concentrated in layer 10. * The Name-Mover/Negative Name-Mover heads consistently appear around layer 9, head 5. * The Backup Name-Mover/Backup (Negative) Name-Mover heads are concentrated around layers 8-10, head 2. * The "Suppression" heatmap generally shows lower scores than the raw "Name-Copying" heatmap, as expected. ### Interpretation The data suggests that layers 7-10 of the GPT-2 model, particularly heads 2-4, are more involved in "Name-Copying" behavior than other layers and heads. This could indicate that these layers are responsible for learning and representing named entities or concepts. The concentration of 'Interp. in the Wild' classifications in layer 10 suggests that these heads are particularly good at generalizing to unseen data. The distinction between "Name-Copying" and "(Suppression) Name-Copying" scores highlights the model's ability to both generate and inhibit name-related information, potentially for controlling the output's relevance and coherence. The scatter plots provide insights into specific head types and their corresponding scores, allowing for a more nuanced understanding of the model's behavior. The fact that the suppression heatmap has lower values than the raw heatmap suggests that the suppression mechanism is working as intended.