• by Laurie Sullivan  @lauriesullivan, April 15, 2025

Apple has built a complicated plan to rely on user data to train its large language models (LLMs). The goal is to “understand aggregate trends for Apple Intelligence,” the company’s artificial intelligence (AI) technology, while promising to protect user data.

In the past Apple had solely used synthetic data to train its AI engine, but found the method ineffective, the company explained in a blog post. It will now use synthetic data but also compare it with data of users who opt in.

The more user data Apple can tap into, the more behavior-based trends it can uncover on its devices to support ad targeting without intruding on user privacy.

The post shares how Apple developed new techniques to analyze use trends to gain insights that improve features while protecting user privacy.

One area is Genmoji. For users who opt in to share Device Analytics with Apple differentially private methods identify popular prompts and prompt patterns.

It provides a mathematical guarantee unique or rare prompts are not discovered, and specific prompts cannot be linked to individual users.

Apple will apply its work on differential privacy to Genmoji, a feature that uses differentially private methods to identify popular prompts and prompt patterns. This approach works by randomly polling participating devices for whether they have seen a particular fragment, and devices respond anonymously with a signal.

The signal Apple receives from the device is not associated with an IP address or any ID that could be linked to an Apple Account.

Through this method, Apple devices will have the ability to determine the synthetic inputs that are closest to real samples. The method, according to Apple, doesn’t access user data, and the data never leaves the device. Apple will then use the most frequently picked synthetic samples to improve its AI text outputs such as email summaries.

Apple uses differential privacy to improve Genmoji, and in upcoming releases will also use this approach, with the same privacy protections, for Image Playground, Image Wand, Memories Creation and Writing Tools in Apple Intelligence, as well as in Visual Intelligence.

The features will apply only to users who opt in to device analytics and product improvement capabilities. Those options are managed in the Privacy and Security tab in the Settings app on the company’s devices.