Apple has ramped up its hiring of artificial intelligence experts, recruiting from PhD programs, posting dozens of job listings and greatly increasing the size of its AI staff, a review of hiring sites suggests and numerous sources confirm.<br />The goal is to challenge Google in an area the Internet search giant has long dominated: smartphone features that give users what they want before they ask.<br />As part of its push, the company is currently trying to hire at least 86 more employees with expertise in the branch of artificial intelligence known as machine learning, according to a recent analysis of Apple job postings.<br />But some experts say the iPhone maker's strict stance on privacy is likely to undermine its ability to compete in the rapidly progressing field.<br />Machine learning experts who want unfettered access to data tend to shy away from jobs at Apple, former employees say.<br />But Apple is strengthening ties to academia to find the talent it will need, attending more industry conferences and discussing its use of tools emerging from university labs, academics say.