Given our touting of recent analytic and machine learning results throughout this book, why haven't doctors been replaced by computers yet? The truth is that there are many obstacles that stand in the way of implementing analytics in healthcare. Ethical issues introduced by this technology are also fiercely debated and must be considered. Finally, while obstacles imply a possibility of being overcome, there are also limitations to this technology, or aspects that likely will not be solved anytime soon. Let's discuss all three of these things in this section.