How does congressmember use AI?

Gen AI has pretty much entered every place where human language is found, whether written or spoken. I was curious about one context: political speech in the American Congress. Was it really used? If so, how was it used?To answer these questions, I first thought about using AI-detectors, but the number of false positives was too high. So, I've built a corpus of words that are overrepresented in AI writing. To select the appropriate, I’ve based myself on previous literature (more details on the methodology here). I then tried to track the rise of those markers throughout Congressional speeches over the last 10 years.This cannot prove whether AI usage increased, only that the markers overused by AI increased.To calculate the increase of the markers, I computed z-scores by taking the distance from the mean divided by the standard deviation. A z-score above 3.0 would indicates a deviation that is statistically significant. The mean and the standard deviation are constructed based on the baseline period (after 2017). I retrospectively applied this same z-score formula to the pre-baseline years (2014–2017) to obtain test years.Here is the graph for the House of Representatives and the Senate.This big graph combines the deviations of all the markers. This means that even if an individual word did not have a statistically significant increase, the aggregate of all markers is still statistically significant.Since I've mostly seen the increase in the House of Representatives, I've decided to focus on it in the rest of the study. Here are the results for individual words in the House of Representatives.The prevalence of the increase in the house of representative might be due to the greater usage of Extensions of Remarks and one-minute speeches in the House of Representatives. Those are the two places where AI seemed to be the most widely used. It might also come from the fact that Senators have been in power for longer and therefore already have established ways of working.In