What is a decision model?
Start hereA ticket, a record, a document or an image, plus a few multiple-choice questions: Which team? Is it urgent? How severe, 1–5?
Instead of writing a reply word by word, the model returns a probability for every allowed answer, for every question, in a single pass. It can only pick from the options you listed.
When the model is clearly sure, act automatically. When it hesitates, ask a person or a bigger model. The rest of this walkthrough shows how to tell the difference.
How DiffusionGemma fills in text (Google DeepMind)
All at onceThree ways software makes these decisions
No training needed + a probability per answer1. Traditional classifiers (e.g. BERT, XGBoost)
Very fast · Needs labeled dataFast and cheap, but needs thousands of labeled examples and retraining every time you add or change a category.
2. Chat models (asked to reply in JSON)
Seconds · Confidence hiddenWorks from plain-English instructions, but writes its answer word by word. Early words can steer later fields, and the text doesn't show whether it was 99% sure or guessing 51/49.
3. Decision models (dgem + DiffusionGemma)
One pass · Probability per answerWorks from plain-English instructions like a chat model, but answers all questions together in one pass and returns a probability for every allowed answer, plus a hesitation score. It is typically much faster than writing the answer word by word, and larger multi-question requests take longer than short ones.
Chat model (writes word by word)
dgem + DiffusionGemma (all blanks at once)
When should the model answer on its own?
Hesitation 57% · HAND OFFWhat happens next
Illustrative example
Confident answers (like urgent = yes) are kept, and the uncertain one (department) is handed to Gemini along with dgem's odds (Technical 76%, Billing 23%) as a hint.
Low hesitation isn't a guarantee. Models tend to favor whichever option is listed first, which can make a coin flip look certain. dgem re-asks benchmark questions in shuffled order on every release and reports the extra flips; correcting each request inside the pass did not help reliably in our tests. Read Confidence beyond Shannon: hesitation-gated decisions →
A document with a hidden instruction
Why a yes/no slot can't leak secrets
Only listed answers
A chatbot can write any of its ~262,000 word pieces. For each question, dgem only reads the probabilities of the allowed answers, like a stencil laid over the output. For injection_detected that's just "yes" and "no"; everything else is ignored, so there's no way to write out secrets through the answer. An attacker can still try to push the yes/no the wrong way, so test detection on your own examples (dgem bench-calibration includes prompt-injection items). The examples below are illustrative:
The full walkthrough, including a hesitation-gating demo and a plain-English glossary, is built into Decision Studio:
run ./bin/dgem serve --port 8090 and open the Concepts tab.