Patent-law trial finds better AI-assisted drafts, uneven learning gains

Giving patent lawyers access to an AI drafting assistant improved their drafts, but the benefits looked different when the tool was taken away. In a three-month randomized trial, senior lawyers performed better on an unaided review task than their control-group peers. Junior lawyers showed no average improvement, despite larger gains on AI-assisted drafting.

The findings come from a working paper dated September 2026, which its authors discussed on Google’s research blog on October 7. The experiment followed 133 practicing lawyers at 11 U.S. intellectual-property firms, all of which had regular, non-exclusive business relationships with Google.

The clearest test of learning came at the end: lawyers had to mark up and correct a hypothetical patent application containing substantive and stylistic errors, without using AI. Those assigned access to the assistant scored 0.32 standard deviations above controls overall. That advantage was concentrated among lawyers with at least seven years of experience, whose scores were 0.45 standard deviations higher than those of senior controls.

The junior results were not simply unchanged across the board. Their scores spread out: fewer mediocre results, but more poor ones and more good ones. The absence of an average gain therefore should not be read as evidence that every junior lawyer had the same experience.

Researchers had assigned two-thirds of the lawyers at each firm early access to a then-unreleased Google Labs patent-writing assistant. The remaining lawyers received some training in using AI but could not use that assistant until the study ended. Separate drafting exercises, conducted after 10 and 90 days, used simulated inventor materials; treatment-group lawyers could use AI for those tasks.

Access raised drafting scores by 0.34 standard deviations at 10 days and 0.38 at 90 days. Blinded expert patent attorneys graded the work, assessing enforceability, accuracy, strategic ambiguity, completeness and clarity. According to the authors, the improvement reflected fewer poor scores and more good ones—not a noticeable increase in excellent work.

The authors suggest that existing expertise may help professionals turn AI-assisted practice into stronger judgment. But the experiment offers a three-month view of one profession, not evidence of career-long learning or decline. The researchers also caution that changes in models and lawyers’ familiarity with AI could affect the results of a repeat trial. Better assisted work and better performance without assistance were distinct outcomes here; they did not improve equally for everyone.