> ## Documentation Index > Fetch the complete documentation index at: https://docs.typesafe.ai/llms.txt > Use this file to discover all available pages before exploring further. # AI primer > Why TypeSafe trains decision models with calibrated probabilities instead of optimizing for generated text. Most AI products are built around a conversation between a model and a person. TypeSafe starts from a different bet: large-scale automation will be dominated by AI-to-AI and AI-to-software interactions, so the machine interface matters more than the chat interface. > **We call this Machine Native Intelligence:** > > AI with software-like properties such as structure, reliability, observability, testability, speed, consistency, and low cost. ## Building prod, not God TypeSafe is not trying to build a model that does everything. It is designed for production systems where code needs a narrow decision it can inspect and act on. Our expectation is that large-scale AI automation will be closer to 99% machine-to-machine interactions and 1% human interaction. That shifts the design target from responses that feel good to read toward outputs that behave predictably inside software. Read the [TypeSafe manifesto](https://typesafe.ai/manifesto). ## Three post-training approaches Pretrained language models have been adapted in two major ways. TypeSafe adds a third. RLHF and RLVR are shown here for context; TypeSafe's training path is RLCD. **Reinforcement learning from human feedback** turned pretrained models into chatbots. It trains models to produce responses people prefer. **Reinforcement learning with verifiable rewards** created reasoning models that are strong at tasks such as mathematics, but slower and more expensive. **Reinforcement learning for calibrated decisions** trains TypeSafe to return decisions and calibrated probabilities instead of generated text. RLHF was used to train InstructGPT and ChatGPT and was [co-invented by Diogo Almeida](https://scholar.google.com/citations?user=0T4y07QAAAAJ\&hl=en), cofounder of TypeSafe. Pretrained language models branch into muted RLHF and RLVR paths and an emphasized RLCD decision-model path. Pretrained language models branch into muted RLHF and RLVR paths and an emphasized RLCD decision-model path. ## RLCD and calibrated decisions RLCD optimizes for a different output contract: * The model does not generate text. * It returns decisions and probabilities. * Higher probability should correspond to a greater chance that the answer is correct. Calibration makes uncertainty usable by software. Across many predictions from a well-calibrated model: * Outcomes assigned a probability of `0.2` should occur about 20% of the time. * Outcomes assigned a probability of `0.8` should occur about 80% of the time. * Outcomes assigned a probability of `1.0` should occur 100% of the time. These rates describe groups of predictions, not a guarantee about any single answer. See [Confidence](/confidence) for guidance on deciding when software should act or escalate. ## The problems with RLHF RLHF teaches a model to say things that people prefer. That objective works well for chatbots, but it can also reward sycophancy and confident-sounding hallucinations. Preference optimization also causes **mode dropping**: the model learns to favor a particular style, such as instruction following, while reducing the probability of other possible outputs. The probability distribution of a base model compared with a narrowed, mode-dropped distribution after RLHF. The probability distribution of a base model compared with a narrowed, mode-dropped distribution after RLHF. An output can be compelling to a person without being reliable enough for unattended automation. Human preference and machine trustworthiness are different optimization targets. Mode dropping is a milder version of **mode collapse**. In the classic generative-adversarial-network failure mode, a generator learns to produce the same kind of output repeatedly because that output continues to fool the discriminator. Repeated characters illustrate a GAN suffering from mode collapse. Repeated characters illustrate a GAN suffering from mode collapse. RLHF remains a good fit for conversational models. TypeSafe's position is that production automation needs a different training objective—one centered on constrained decisions and calibrated uncertainty.