Voters gradually change their opinions when presented the facts
In this study, respondents were given a factual question like "From 2009, when President Obama took office, to 2012, median household income adjusted for inflation in the United States fell by more than 4 percent" and asked to rate it as "True" or "False." Over the course of four subsequent rounds, they were given signals that the information was indeed accurate or not and told that these signals were right 75% of the time. The results indicate that respondents updated their beliefs towards the correct answer regardless of their partisan preference. The study's elaborate design makes it hard for fact-checkers to draw real life lessons. However, it does seem to offer additional evidence that fact-checking doesn't fall on deaf ears.