Algorithm & Signal Overview
About 378 wordsAbout 1 min
2026-07-06
Every data-scheduling method in DataFlex-RL reduces to a signal (a scalar/tensor computed per token / sample / group / domain) fed to a rule (select / reweight / mix). This page is the single place to see, across all three mechanisms, what signal each algorithm keys on and where it comes from.
The research frontier is mostly about new signals — the rules (top-k, softmax, band, UCB, threshold, max-variance) are shared and interchangeable.
Master table
| Algorithm | Mechanism | Signal | Granularity | Source (arXiv) |
|---|---|---|---|---|
threshold_band | select | group solve-rate / any score in a band | prompt/group | DAPO 2503.14476 |
difficulty_filtering | select | group pass-rate, keep 0.2–0.8 band | prompt/group | 2504.03380 |
gfpo | select | response length + reward (conciseness / token-efficiency), top-k per group | response(group) | 2508.09726 |
pods_maxvar (max_variance) | select | per-response reward, max-variance subset | response(group) | 2504.13818 |
topk_fraction | select | per-sample |advantage|, keep top fraction | prompt | generic (PER-style) |
advantage_reweight | reweight | per-token π_θ (probability), damp low-prob tokens | token | 2505.12929 |
per_advantage | reweight | per-sample |advantage| (w=|A|^α) | prompt | PER 1511.05952 |
softmax | reweight | any per-sample score (softmax(s/T)) | prompt | generic baseline |
difficulty_band | reweight | per-seq reward quantile band | prompt | generic (cf. ODSW) |
dump_ucb | mix | per-domain |advantage| + UCB | domain | 2504.09710 |
tscl | mix | per-domain reward slope (learning progress) | domain | 1707.00183 |
reward_gap | mix | per-domain mean reward (favor lagging) | domain | generic (cf. DoReMi) |
static | mix | fixed proportions | domain | baseline |
Signals grouped by axis
- Reward level / pass-rate —
difficulty_filtering,pods_maxvar,difficulty_band,reward_gap,threshold_band. - |advantage| —
topk_fraction,per_advantage,softmax(as used),dump_ucb. - Reward slope / learning progress (rate of change, a distinct axis from reward level) —
tscl. - Token probability —
advantage_reweight. - Length / token-efficiency —
gfpo.
On provenance (honest note)
Most algorithms map a published method's core idea onto DataFlex's Scorer→Actuator abstraction; a few (topk_fraction, softmax, difficulty_band, reward_gap, static) are generic mechanism knobs the abstraction provides, not faithful reproductions of a single paper. Where a paper is named, the implementation captures its signal + rule, not necessarily every training trick in the original. See the survey (Awesome-RL-OPD-Data) for evidence grades and full sourcing.