Words Speak Louder Than Order: A Behavioral Evaluation of Gemma 4
Organizations: Google
Abstract
When a language model receives two conflicting documents as input, how does it decide which one to prioritize? Does it rely on how the sources are framed or the presentation order of the documents? We evaluated this behavior on Google's pre-trained Gemma 4-e4b model across a targeted behavioral suite (n = 13 items, 784 forward passes in short, single-turn contexts) using a completely counterbalanced experimental design. This setup allowed us to mathematically isolate the specific effects of source framing and reading position, while ensuring the model's natural vocabulary biases were canceled out. Across ten test conditions, we discovered the following: 1. Source framing heavily overpowers reading position. When directly competing, the semantic framing of a source (such as presenting it as an official guideline or a fresh update) had a significantly stronger impact on the model's final answer than the presentation order of the document. 2. The model favors the first document it reads, but this bias is highly variable. While the model consistently demonstrated a primacy effect (preferring the first document presented), the actual strength of this bias fluctuated by at least a factor of 5 based solely on the surface wording. 3. Overall structural repetition, not short copy-cues, drives positional bias. The model's preference for the first document is not a mechanical reaction to short, repetitive trigger phrases, such as "is [Answer]". However, the primacy effect does increase significantly when the two competing documents are structurally identical, using word-for-word verbatim templates. Introducing variation in the overall wording between the two sources reduces this positional bias.
Figures & tables
| Cell | First block | Second block |
|---|---|---|
| Stale (Agile) | Recent (Waterfall) | |
| Recent (Waterfall) | Stale (Agile) | |
| Stale (Waterfall) | Recent (Agile) | |
| Recent (Agile) | Stale (Waterfall) |
| Dial type | Settings | What it changes |
|---|---|---|
| Header wording | neutral , framed | Whether the blocks are: neutral: labeled with an unbiased identifier blandly (e.g., “Document A”) framed: labeled as an official guideline (authority) or a fresh team update (recency). (e.g., authority: “Official Guideline:”) (e.g., recency: “Team Update:”) |
| Body wording | verbatim, mixed, loaded | The two block bodies are: verbatim: word-for-word identical except the answer word (e.g., “The required system is [Answer].”) mixed: reworded using difference sentence structures for each block. (e.g., Block 1: “The required system is [Answer],”) (e.g.,Block 2: “[Answer] is the recommended method.”) loaded: carries the framed meaning in the sentence itself. (e.g., “Official guidelines state the required system is [Answer].”) |
| Cue count | 0, 1, 2 | How many times the exact word pattern appears. (e.g. “is {e}”) |
| Test Condition | Header Wording | Body Wording | Cue Count |
|---|---|---|---|
| T1 | neutral | verbatim | 2 |
| T1c | neutral | verbatim | 0 |
| T2 | neutral | mixed | 1 |
| T2c | neutral | mixed | 0 |
| T3 | framed | verbatim | 2 |
| T3c | framed | verbatim | 0 |
| Cell | Header | Body | Cues | Serial Position (half-effect, nats) | 95% CI | Items Showing Primacy | 90% CI clears -0.15 |
|---|---|---|---|---|---|---|---|
| T1 | neutral | verbatim | 2 | -0.485 | [-0.611, -0.283] | 12/13 | [-0.592, -0.318] |
| T1c | neutral | verbatim | 0 | -0.884 | [-1.074, -0.708] | 13/13 | [-1.044, -0.735] |
| T2 | neutral | mixed | 1 | -0.377 | [-0.496, -0.227] | 12/13 | [-0.478, -0.252] |
| T2c | neutral | mixed | 0 | -0.635 | [-0.902, -0.452] | 13/13 | [-0.854, -0.478] |
| T3 | framed | verbatim | 2 | -0.679 | [-0.848, -0.520] | 13/13 | [-0.822, -0.543] |
| T3c | framed | verbatim | 0 | -0.569 | [-0.739, -0.429] | 13/13 | [-0.713, -0.452] |
| Contrast | Description | Filtered Dataset (13 items, primary) | Unfiltered Dataset (14 items) |
|---|---|---|---|
| A1 | Cue removal, neutral header (T1c - T1) | -0.400 [-0.578, -0.237] * | -0.407 [-0.573, -0.251] * |
| A2 | Cue removal, authority header (T3c - T3) | +0.110 [-0.081, +0.287] | +0.074 [-0.112, +0.257] |
| A3 | Average of A1 and A2, descriptive only | -0.145 [-0.290, +0.010] | -0.166 [-0.306, -0.011] * |
| A4 | Do A1 and A2 arms differ? | -0.509 [-0.687, -0.316] * | not computed |
| Quantity | Estimate | 95% CI |
|---|---|---|
| Source framing (header + body together) | +1.054 | [+0.907, +1.258] * |
| Serial position (half-effect) | -0.265 | [-0.421, -0.137] * |
| Residual check (block-order null control) | +0.011 | [-0.058, +0.087] |
| Token (base word preference) | +0.003 | [-0.135, +0.165] |
| Contrast | Description | Filtered Dataset ( ) | Unfiltered Dataset ( ) |
|---|---|---|---|
| D1 | Framing vs. position margin, cue-free (T5b) | +0.774 [+0.585, +0.966] * | +0.806 [+0.616, +0.991] ** |
| D2 | Framing vs. position margin, with cues (T5) | +0.316 [+0.188, +0.434] * | +0.317 [+0.199, +0.428] * |
| D3 | Effect of removing cues on framing (T5b - T5) | +0.539 [+0.330, +0.843] * | +0.583 [+0.366, +0.874] * |
| Contrast | Description | Filtered Dataset ( ) | Unfiltered Dataset ( ) |
|---|---|---|---|
| C1 | Effect of authority header, mixed bodies (T4c - T2c) | +0.153 [-0.011, +0.352] | +0.123 [-0.033, +0.322] |
| C2 | Effect of authority header, verbatim bodies (T3c - T1c) | +0.315 [+0.172, +0.420] * | +0.296 [+0.166, +0.403] * |
| C3 | The interaction (C1 - C2) | -0.162 [-0.303, -0.034] * | -0.173 [-0.301, -0.048] * |
| ID | Purpose | Filtered Dataset ( ) | Unfiltered Dataset ( ) | Status |
|---|---|---|---|---|
| A1 | Neutral cue removal | -0.400 * | -0.407 * | Inferential |
| A2 | Authority cue removal | +0.110 | +0.074 | Inferential (null) |
| A3 | Pooled cue removal | -0.145 | -0.166 * | Descriptive only |
| A4 | Arm heterogeneity test | -0.509 * | not computed | Inferential; post-dates log |
| B1 | Partial cue removal | +0.108 | +0.110 | Descriptive (confounded) |
| B2 | Mixed-body cue removal | -0.258 * | -0.275 * | Descriptive (confounded) |
| Crossing | Block order | Entity-role assignment | Resulting prompt structure |
|---|---|---|---|
| 1 | Authority first | Agile = Stale, Waterfall = Recent | Official Guideline: Use Agile. Team Update: Use Waterfall. |
| 2 | Authority first | Waterfall = Stale, Agile = Recent | Official Guideline: Use Waterfall. Team Update: Use Agile. |
| 3 | Recent first | Agile = Stale, Waterfall = Recent | Team Update: Use Waterfall. Official Guideline: Use Agile. |
| 4 | Recent first | Waterfall = Stale, Agile = Recent | Team Update: Use Agile. Official Guideline: Use Waterfall. |
| Nat value | CI | Odds (A to B) | Prob. of A | Prob. of B | Model’s preference |
|---|---|---|---|---|---|
| +2.0 | [+1.80, +2.20] | 7.39 to 1 | 88% | 12% | Overwhelming preference for Option A. |
| +1.0 | [+0.80, +1.20] | 2.72 to 1 | 73% | 27% | Strong preference for Option A. |
| 0 | [-0.20, +0.20] | 1.00 to 1 | 50% | 50% | Indifference. The model is guessing. |
| -1.0 | [-1.20, -0.80] | 1 to 2.72 | 27% | 73% | Strong preference for Option B. |
| -2.0 | [-2.20, -1.80] | 1 to 7.39 | 12% | 88% | Overwhelming preference for Option B. |
| Type | Role | Wording |
|---|---|---|
| Cued | Authority | Official guidelines state that for project planning, the required configuration is {e} . |
| Cue-Free | Authority | {e} is the required configuration for project planning, per official guidelines. |
| Cued | Recency | Update: The new updated specification for project planning is now {e} . |
| Cue-Free | Recency | {e} is the newly updated specification for project planning, effective now. |
| Cell | Header | Body | Cues | Serial Position (half-effect, nats) | 95% CI | Items Showing Primacy | 90% CI clears -0.15 |
|---|---|---|---|---|---|---|---|
| T1 | neutral | verbatim | 2 | -0.485 | [-0.611, -0.283] | 12/13 | [-0.592, -0.318] |
| T1c | neutral | verbatim | 0 | -0.884 | [-1.074, -0.708] | 13/13 | [-1.044, -0.735] |
| T2 | neutral | mixed | 1 | -0.377 | [-0.496, -0.227] | 12/13 | [-0.478, -0.252] |
| T2c | neutral | mixed | 0 | -0.635 | [-0.902, -0.452] | 13/13 | [-0.854, -0.478] |
| T3 | framed | verbatim | 2 | -0.679 | [-0.848, -0.520] | 13/13 | [-0.822, -0.543] |
| T3c | framed | verbatim | 0 | -0.569 | [-0.739, -0.429] | 13/13 | [-0.713, -0.452] |
| Contrast | Description | Filtered Dataset (13 items, primary) | Unfiltered Dataset (14 items) |
|---|---|---|---|
| A1 | Cue removal, neutral header (T1c - T1) | -0.400 [-0.578, -0.237] * | -0.407 [-0.573, -0.251] * |
| A2 | Cue removal, authority header (T3c - T3) | +0.110 [-0.081, +0.287] | +0.074 [-0.112, +0.257] |
| A3 | Average of A1 and A2, descriptive only | -0.145 [-0.290, +0.010] | -0.166 [-0.306, -0.011] * |
| A4 | Do A1 and A2 arms differ? | -0.509 [-0.687, -0.316] * | not computed |
| Test Condition | Header Wording | Body Wording | Cue Count |
|---|---|---|---|
| T5 | framed | loaded | 2 |
| T5b | framed | loaded | 0 |
| Quantity | Estimate | 95% CI |
|---|---|---|
| Source framing (header + body together) | +1.054 | [+0.907, +1.258] * |
| Serial position (half-effect) | -0.265 | [-0.421, -0.137] * |
| Residual check (block-order null control) | +0.011 | [-0.058, +0.087] |
| Token (base word preference) | +0.003 | [-0.135, +0.165] |
| Contrast | Description | Filtered Dataset ( ) | Unfiltered Dataset ( ) |
|---|---|---|---|
| D1 | Framing vs. position margin, cue-free (T5b) | +0.774 [+0.585, +0.966] * | +0.806 [+0.616, +0.991] ** |
| D2 | Framing vs. position margin, with cues (T5) | +0.316 [+0.188, +0.434] * | +0.317 [+0.199, +0.428] * |
| D3 | Effect of removing cues on framing (T5b - T5) | +0.539 [+0.330, +0.843] * | +0.583 [+0.366, +0.874] * |
| Contrast | Description | Filtered Dataset ( ) | Unfiltered Dataset ( ) |
|---|---|---|---|
| C1 | Effect of authority header, mixed bodies (T4c - T2c) | +0.153 [-0.011, +0.352] | +0.123 [-0.033, +0.322] |
| C2 | Effect of authority header, verbatim bodies (T3c - T1c) | +0.315 [+0.172, +0.420] * | +0.296 [+0.166, +0.403] * |
| C3 | The interaction (C1 - C2) | -0.162 [-0.303, -0.034] * | -0.173 [-0.301, -0.048] * |
Framing Effects in Language Models
Framing effects in language models study how wording, context, perspective, and presentation alter model judgments and outputs.
See all 51 papers