Parameter-efficient fine-tuning (LoRA family)
BitFit
BitFit: Simple Parameter-efficient Fine-tuning for Transformer-based Masked Language-models
Heavily superseded — a standard baseline that newer methods routinely beat
7 papers critique it · 28 beat it on benchmarks
What papers say
Verbatim critique sentences, each from a paper that cites BitFit as a baseline.
Yet, because weight matrices are not changed %the bias terms remain constant across inputs % %(see Section~sec: method), %variation between samples are not taken into account during fine-tuning. As a result, % they may not reach the performance achieved by other methods, such as Low-Rank Adaptation (LoRA) hu2021lora, pu2023empirical.
“Unlike the previous literature like Liu2022FewShotPF or BenZaken2021BitFitSP, we introduce a novel prompt-aware mechanism to the PEFT method.”
“This includes methods previously considered less effective, such as BitFit~zaken2022bitfit, which FT only the bias terms of the frozen backbone.”
“Research based on sparse methods zaken2021bitfit optimizes the bias parameter to reduce cost and improve the performance of the model during specific tasks but faces problems in dealing with real data.”
“BitFit is susceptible to catastrophic forgetting when the target task has a large zero-shot silhouette score”
“We hypothesize, however, that the bias may not necessarily be the optimal component of BERT for parameter-efficient fine-tuning, and similar/better performance could be obtained by training a smaller number of parameters if the optimal component is chosen.”
“BitFit method zaken2021bitfit updates only the bias parameters, resulting in a substantial reduction in the number of trainable parameters, but at the cost of suboptimal performance.”
Beaten on benchmarks
Head-to-head results where a newer method reports beating BitFit. Values are copied from the source paper's tables — verify against the cited paper.
LoRA beats BitFit
57.25 vs 16.61
ILoRA beats BitFit
0.0533 vs 0.1271
AbsRel · [NYU → KITTI]
1LoRA: Summation Compression for Very Low-Rank AdaptationQuIC beats BitFit
28.14 vs 19.95
Pareto · [DeBERTaV3-base]
QuIC: Quantum-Inspired Compound Adapters for Parameter Efficient Fine-TuningLoRA-LinProj beats BitFit
61.0 vs 44.4
Acc. · [Mamba model, CIFAR-10]
Parameter-Efficient Fine-Tuning of State Space ModelsDP-DyLoRA beats BitFit
58.0 vs 85.2
Heart-LoRA beats BitFit
77.2 vs 65.2
MiLoRA beats BitFit
77.8 vs 65.9
Overall Accuracy · [LlaMA-2 7B single-task]
MiLoRA: Efficient Mixture of Low-Rank Adaptation for Large Language Models Fine-tuningCleaR_{\text{BitFit}} beats BitFit
51.1 vs 43.5
KronA+ beats BitFit
80.19 vs 69.67
DEFLECT beats BitFit
64.6 vs 56.5
Avg. Perf. · [Scale-MAE]
Parameter-Efficient Adaptation of Geospatial Foundation Models through Embedding DeflectionState-offset Tuning beats BitFit
57.4 vs 51.25725269
Spider (All) · [Mamba 1.4B]
State-offset Tuning: State-based Parameter-Efficient Fine-Tuning for State Space ModelsIISAN beats BitFit
4.14 vs 3.76
What to use instead
Recent methods in the same sub-problem, not yet superseded in the knowledge base — arXiv benchmark leaders, not vetted production recommendations.
- May 29, 2026
- May 28, 2026
- May 19, 2026
- May 15, 2026
- May 12, 2026
- May 11, 2026
- May 11, 2026
- May 8, 2026
- May 5, 2026
- May 5, 2026
- May 5, 2026
- RDP LoRARDP LoRA: Geometry-Driven Identification for Parameter-Efficient Adaptation in Large Language ModelsApr 21, 2026