Facebook Inc. FB, +0.46% said Tuesday that it would provide more "background information" about articles and publishers who appear in a user's news feed. Facebook will now show all U.S. users who click a small information button the Wikipedia entry for particular publisher, related articles about a topic, more articles from a publisher, and a list of friends who've shared a particular piece. Some of these changes stem from a small test that Facebook rolled out last year. The company is starting a new test through which it will offer information about a particular article's author and show that writer's Wikipedia page. Facebook has been criticized for the ways in which propaganda was able to spread on its site during the 2016 election. Shares are down 0.6% in midday trading Tuesday but up 9% over the past 12 months, compared with a 9.5% gain for the S&P 500 SPX, +1.26%