2. Spam or Ham?

If you use email (I suspect you do!), chances are that you see machine learning at work on a daily basis. Your email client probably includes some spam filter mechanism, which automatically identifies blatantly unwanted promotional materials in your incoming messages and discreetly sends them into oblivion in a "spam folder." It spares you the annoyance of having to delete these messages manually one by one; it will also save you from inadvertently clicking potentially harmful links. This is typical of how machine learning, when well done, can make human life better. Computers are great at performing repetitive tasks and being thorough about it; by automatically taking care of tedious activities and saving us from mistakes, they enable us humans to focus on more interesting, thought-engaging activities.