This repository contains a PEFT/LoRA adapter for Qwen/Qwen2.5-1.5B-Instruct trained by the FakeNews research pipeline. The model is intended to study whether an open-source instruction model can classify misinformation when given different amounts and qualities of source context.
This artifact is an adapter, not a standalone full model. Load it with the base model listed above.
Model Details
Model Description
Developed by: Jay Bell Compaan
Funded by: Kingston University
Shared by: Jay Bell Compaan
Model type: PEFT LoRA adapter for causal language modeling
Base model:Qwen/Qwen2.5-1.5B-Instruct
Language(s) (NLP): The base model is multilingual; this adapter was trained on mixed-source misinformation datasets with English and non-English records represented in the source corpora.
The adapter was trained to produce a compact JSON response for binary misinformation classification (real or fake) plus confidence, explanation, reasoning signals, and whether external evidence is required.
Use this model for research experiments on misinformation classification and context ablation. It is suitable for comparing model behavior across context conditions such as full context, minimal context, or intentionally misleading context when the broader FakeNews pipeline is used.
The model should not be used as a final authority for fact checking, moderation, legal decisions, medical decisions, election operations, or other high-stakes determinations. Its outputs should be treated as experimental model predictions requiring human review and external evidence.
Direct Use
Direct use means loading the Qwen base model with this adapter and prompting it to classify a claim or source excerpt. The intended direct use is exploratory research: inspect whether the adapter returns the expected JSON schema and compare its behavior across carefully controlled prompts.
Expected output shape:
json
1{2"classification":"fake",3"confidence":0.66,4"explanation":"Short explanation based on the provided claim and context.",5"reasoning_signals":["dataset: ClaimReview","context text available"],6"requires_external_evidence":false7}
Generated JSON should be parsed and validated by downstream code before use.
Downstream Use
Downstream use is expected through the FakeNews experimental pipeline, where the same records can be evaluated under full, minimal, and misleading context conditions. The adapter can also be used as one point in a multi-model comparison, provided each base model receives its own separately trained adapter.
Example downstream tasks:
Measuring performance shifts as context is reduced.
Comparing text-only and image-text-capable base models.
Producing validation/test reports for research artifacts.
Studying whether model explanations change with misleading or incomplete context.
Out-of-Scope Use
This model is out of scope for:
Automated content moderation or user enforcement.
Determining whether a person, organization, publication, or community is trustworthy.
Election, legal, medical, financial, or safety-critical decisions.
Real-time misinformation policing without human fact-checking.
Claims requiring fresh web evidence, private data, or source verification not present in the prompt.
Applying this adapter to unrelated base models. LoRA adapters are not generally portable across arbitrary model architectures.
Bias, Risks, and Limitations
This is a research artifact, not a production fact-checking system.
The adapter was trained in full context mode for this run. Minimal and misleading context comparisons require separate evaluation runs or additional adapters.
The model may learn dataset-specific artifacts, publisher patterns, wording conventions, class imbalance, or label mapping decisions rather than robust factual verification.
ClaimReview dominates the sampled gate evaluations, so aggregate metrics may hide weaker performance on smaller datasets.
Confidence values are generated by the target response format and should not be treated as calibrated probabilities.
The artifact is text-only. The wider FakeNews codebase supports image-aware Hugging Face inference for compatible vision-language models, but this adapter was not trained with image tensors.
The run is not release ready under the configured diagnostic gate because test_confidence_mean fell below the threshold.
Recommendations
Users should:
Treat outputs as hypotheses for research review, not verified facts.
Keep human review and source evidence in the loop.
Report metrics by dataset and context mode rather than relying only on aggregate accuracy.
Validate output JSON before consuming predictions.
Re-run evaluation when changing context mode, base model, sampling, or prompt format.
Train one adapter per base model instead of reusing this adapter across unrelated model families.
How to Get Started with the Model
Install compatible dependencies, then load the base model and adapter:
python
1from peft import PeftModel
2from transformers import AutoModelForCausalLM, AutoTokenizer
34base_model_id ="Qwen/Qwen2.5-1.5B-Instruct"5repo_id ="JayNightmare/FakeNews"67tokenizer = AutoTokenizer.from_pretrained(base_model_id)8model = AutoModelForCausalLM.from_pretrained(base_model_id)9model = PeftModel.from_pretrained(model, repo_id, subfolder="adapter")1011prompt ="""Return JSON only.
1213Classify this claim as real or fake and explain briefly:
14Claim: The moon is made of cheese.
15Context: This is a known humorous false claim, not a factual astronomy statement.
16"""1718inputs = tokenizer(prompt, return_tensors="pt")19outputs = model.generate(**inputs, max_new_tokens=160)20print(tokenizer.decode(outputs[0], skip_special_tokens=True))
For local bundle use from the generated model bundle directory, replace the final load line with PeftModel.from_pretrained(model, "adapter").
Training Details
Pipeline Overview
Training pipeline diagram
Training Data
The adapter was trained on cleaned splits from the FakeNews master dataset. The combined corpus includes records from:
Google Fact Check grounding was disabled for this run.
Training Procedure
Preprocessing
Source-specific dataset loaders convert records into a canonical UnifiedRecord schema. The cleaning pipeline removes empty or very short records, normalizes whitespace, preserves provenance metadata, maps source labels to internal real/fake labels, and exports deterministic cleaned train/validation/test splits.
Each training record is rendered with the FakeNews prompt builder using context_mode=full and context_budget=1.0. The target assistant message is deterministic JSON supervision containing classification, confidence, explanation, reasoning signals, and whether external evidence is required.
Training preprocessing diagram
Training Hyperparameters
Hyperparameter
Value
Training regime
CUDA training; exact floating-point dtype was not recorded in the artifact summary
Wall-clock training time was not recorded in the artifact metadata.
Evaluation
Testing Data, Factors & Metrics
Testing Data
Validation and test scoring used deterministic subsets of up to 1,000 records from the cleaned validation and test splits. The full cleaned split sizes were 54,052 validation records and 54,053 test records.
Metrics include accuracy, precision, recall, F1, confusion matrix counts, support, confidence statistics, explanation counts, and release-gate diagnostics. These metrics are research diagnostics, not production certification.
Results
Split
Accuracy
Precision
Recall
F1
Support
Validation
0.9050
0.9597
0.9203
0.9396
1,000
Test
0.9020
0.9441
0.9322
0.9381
1,000
Confidence statistics:
Split
Mean
Min
Max
Validation
0.6668
0.66
0.69
Test
0.6667
0.66
0.69
Test-set metrics by dataset:
Dataset
Accuracy
Precision
Recall
F1
Support
ClaimReview
0.9297
0.9619
0.9633
0.9626
725
Fakeddit
0.8036
0.8105
0.7476
0.7778
224
FakeNewsNet
0.9375
1.0000
0.6667
0.8000
48
MuMiN
1.0000
1.0000
1.0000
1.0000
3
Summary
The adapter passed the configured accuracy, F1, train/validation F1-gap, validation/train loss-ratio, and underfit-loss checks. It did not pass the test_confidence_mean >= 0.70 check (actual = 0.6667). Because the run used gate_policy=report, the artifact was still generated for research comparison, but release_ready=false.
Model Examination
No separate interpretability or mechanistic analysis was performed for this artifact. Evaluation currently relies on aggregate and disaggregated classification metrics plus sampled generated explanations. Future examination should inspect failure cases by dataset, source publisher, context condition, and label class.
Environmental Impact
Carbon emissions were not measured for this run. The artifact metadata records CUDA training but does not record the exact GPU model, provider, region, power draw, or wall-clock duration.
The base architecture is Qwen/Qwen2.5-1.5B-Instruct, adapted with PEFT LoRA modules for causal language modeling. The adapter objective is supervised instruction tuning: given a misinformation classification prompt, generate JSON with a binary label and short explanatory fields.
LoRA configuration:
Setting
Value
PEFT type
LORA
PEFT version
0.19.1
Task type
CAUSAL_LM
Rank (r)
16
Alpha
32
Dropout
0.05
Bias
none
Inference mode
true
Adapter weights
adapter_model.safetensors
Compute Infrastructure
The training script used the repository's manual Hugging Face adapter trainer at src/train_hf_adapter.py. It loads the base model, attaches LoRA modules with PEFT, tokenizes supervised chat examples, trains for one epoch, evaluates on the explicit validation split, then scores deterministic gate subsets from train/validation/test.
Hardware
CUDA device was used.
RTX 5070 Laptop GPU
RAM: 32 GB
CPU: Intel(R) Core(TM) 9 270H
Disk: 1 TB SSD
OS: Windows 11 Edu
Software
PEFT 0.19.1
Transformers-compatible causal language model loading via AutoModelForCausalLM
Hugging Face tokenizer and chat template assets included in the adapter directory
The paper is currently being drafted for submission to a peer-reviewed conference.
BibTeX:
bibtex
1@misc{compaan_fakenews_qwen_adapter_2026,
2 title = {FakeNews Qwen LoRA Adapter for Context-Aware Misinformation Classification},
3 author = {Compaan, Jay Bell and Peiling, Yi and Charles, Michael J. C.},
4 year = {2026},
5 note = {Research artifact; paper in preparation}
6}
APA:
Compaan, J. B., Peiling, Y., & Charles, M. J. C. (2026). FakeNews Qwen LoRA Adapter for Context-Aware Misinformation Classification. Research artifact; paper in preparation.
Glossary
Adapter: A small set of learned parameters loaded on top of a base model.
LoRA: Low-Rank Adaptation, a parameter-efficient fine-tuning method.
Context budget: Fraction of available contextual information retained in prompts.
Context ablation: Evaluation that varies available context to measure prediction changes.
Gate policy: Repository setting that determines whether validation/test checks only report metrics or block artifact generation.
Release ready: Whether all configured diagnostic gate checks passed.
Artifact ready: Whether the adapter artifact was generated for research use.
