Last week, the Board of Immigration Appeals (BIA) addressed the appropriate standards of review in the asylum context. Specifically, the BIA overturned its previous precedent and determined that an Immigration Judge's predictions about the likelihood of future events are factual findings, subject to a clearly erroneous standard on review. However, whether an asylum applicant has established an objectively reasonable fear of persecution based on the events that the Immigration Judge found may occur upon the applicant’s return to the country of removal is a legal determination that remains subject to de novo review. Accordingly, the BIA "will accept the underlying factual findings of the Immigration Judge unless they are clearly erroneous, and  will review de novo whether the underlying facts found by the Immigration Judge meet the legal requirements for relief from removal or resolve any other legal issues that are raised."
The full text of Matter of Z-Z-O- can be found here: https://edit.justice.gov/sites/default/files/pages/attachments/2015/05/26/3838.pdf