UMHLAHLANDLELA Wobuchwepheshe

Reinforcement Fine-Tuning with Graders

Reinforcement fine-tuning (RFT) trains a model by having it generate answers, scoring those answers with a grader, and updating the model to make high-scoring answers more likely, rather than teaching it to copy example outputs.

  • 4 amaminithi afundiwe
  • Igcine ukubuyekezwa
Kuleli khasi4 amaminithi afundiwe
  1. Uhlolojikelele
  2. I-Deep Dive
  3. I-Strategic Impact
  4. The Future of Reinforcement Fine-Tuning with Graders
  5. Ukuqaliswa Komhlaba Wangempela
  6. Izingozi & Guardrails
  7. Ukuqalisa Umhlahlandlela
  8. Qhubeka Uhlole
  9. Imibuzo evame ukubuzwa

Uhlolojikelele

It matters because it can improve reasoning on tasks where a correct answer is easy to check but hard to demonstrate step by step. Its main risk is reward hacking, where the model learns to please the grader instead of solving the task.

I-Deep Dive

Standard supervised fine-tuning shows the model an input and the exact output you want, and trains it to imitate. That works when you can write good target outputs, but it teaches the surface form of answers rather than the process of reaching them. Reinforcement fine-tuning works differently. For each training prompt, the model samples one or more candidate answers. A grader assigns each a score, often between 0 and 1. The training algorithm then adjusts the model so that answers scoring above average become more likely and those below average less likely. Over many rounds, the model keeps the reasoning patterns that earn reward. Graders come in a few kinds. Exact or string-match graders check whether a final answer equals a reference. Programmatic graders run code, such as unit tests or a numerical tolerance check. Model-based graders use another language model with a rubric to judge qualities that are hard to check mechanically. Graders can also give partial credit, which gives the model a smoother signal. RFT suits tasks with verifiable or reliably gradable answers where experts agree on what is correct: classification with defined labels, maths, code, structured extraction, and some specialised judgement tasks. It is a poor fit where quality is subjective and graders disagree. OpenAI previewed a reinforcement fine-tuning service in December 2024, and reasoning models more broadly have been trained with reinforcement learning on verifiable rewards. The central failure mode is reward hacking. The model optimises the grader, not your intent. If a grader only checks the final line, the model may produce a correct-looking final line with broken reasoning. If a model grader likes length or confident wording, outputs drift toward those traits. A common misconception is that a higher training reward means a better model; it only means a better score from that grader.

I-Strategic Impact

Izindleko kanye nesabelomali

Izinqumo zezakhiwo ziqhuba ukusebenza kanye nezindleko zokusebenza iminyaka.

Izinqumo ezicacile

Imfundo yobuchwepheshe isiza amaqembu ukuthi akhethe isitaki esifanele, hhayi nje esisha.

Ukulawulwa kwekhwalithi

Izinketho ezingcono zobunjiniyela zinciphisa izehlakalo ezinokwethenjelwa ekukhiqizeni.

The Future of Reinforcement Fine-Tuning with Graders

Reinforcement learning on gradable tasks has become an important part of how reasoning models are trained, and hosted services are making RFT available to smaller teams. Progress is likely to depend less on the training algorithm and more on grader quality, since a model can only become as good as the signal it is optimised against. Research into more robust graders, multiple independent graders and better detection of reward hacking is active. For most organisations, the practical question will remain whether they can define correctness clearly enough to grade it.

Ukuqaliswa Komhlaba Wangempela

A tax software team trains a model to classify expense items into the correct category code, with a grader that checks the predicted code against a labelled answer.

A company building a coding assistant rewards generated functions by running them against unit tests, so the reward reflects whether the code actually works.

A medical research group trains a model to rank likely genes given a list of symptoms, with a grader that gives partial credit when the correct gene appears near the top of the ranking.

A team uses a model-based grader to score customer email replies for accuracy and tone, then discovers the policy has learned to add flattering phrases the grader over-rewards.

Izingozi & Guardrails

  • Ukuthuthukisa ibhentshimakhi eyodwa kungafihla ubuthakathaka obubanzi besistimu.

  • Izindleko zengqalasizinda nezokulungisa zivame ukubukelwa phansi.

  • Izikhala zokuphepha nokubonakala zingakhula njengoba izinhlelo ziba nzima kakhulu.

Ukuqalisa Umhlahlandlela

  1. Chaza ukubambezeleka, ikhwalithi, nezindleko ezihlosiwe ngaphambi kokuqaliswa.

  2. Ibhentshimakhi ngaphansi komthwalo wangempela nezimo zedatha.

  3. Ukuqapha amathuluzi amaphutha, ukukhukhuleka, nomthelela wabasebenzisi.

  4. Lungiselela izindlela zokuhlehlisa nezigameko ngaphambi kokukala.

Qhubeka Uhlole

Free newsletter

Get the daily AI briefing

Three verified AI stories every weekday morning, written in plain English. Free forever, no ads.

One email each weekday. Unsubscribe in one click. We never sell or share your address.

Test yourself

Take the Reinforcement Fine-Tuning with Graders quiz

Instant feedback on every answer, and a shareable certificate with a verifiable ID once you pass a course.

Qala imibuzo

Support free AI education. AI Understanding is a 501(c)(3) nonprofit — no ads, no paywall, ever. Make a donation

Imibuzo evame ukubuzwa

What is Reinforcement Fine-Tuning with Graders?

Reinforcement fine-tuning (RFT) trains a model by having it generate answers, scoring those answers with a grader, and updating the model to make high-scoring answers more likely, rather than teaching it to copy example outputs. It matters because it can improve reasoning on tasks where a correct answer is easy to check but hard to demonstrate step by step. Its main risk is reward hacking, where the model learns to please the grader instead of solving the task.

How does reinforcement fine-tuning differ from supervised fine-tuning?

Supervised fine-tuning imitates targets; RFT samples answers, scores them with a grader and reinforces high-scoring ones.

Which grader type would you use to check that generated code actually works?

Programmatic graders can execute code against tests, directly measuring whether it works.

Which task is the poorest fit for RFT according to the guide?

RFT needs a reliable grade. When experts disagree about what is correct, the reward signal is noisy.

In Reinforcement Fine-Tuning with Graders: what is reward hacking?

Reward hacking happens when optimisation exploits weaknesses in the grader, raising scores without improving true quality.

Why do prompts where every sample gets the same score provide little learning signal in group-relative methods like GRPO?

GRPO uses relative scores within a group as the advantage. If all scores match, there is no difference to learn from.