I went to Arizona earlier this month to see what the college of the future might look like. What I found is an exciting new era of higher education that will help more students get a great, personalized education at an affordable price. This future may not always include the lecture halls, dormitories, and other features of the traditional college experience. Instead, the colleges I visited are experimenting with ways for students to get their degrees online, allowing them to take courses any place and at any time. These " _ ," as they are sometimes called, are at the forefront of the effort to broaden access to higher education, especially for low-income students with full-time jobs and families. During my visit, I heard encouraging stories of students who were taking advantage of these flexible learning models to pursue degrees that could put them on paths to new careers. One of those students was Shawn Lee. He had a compelling story: After dropping out of college decades ago, he found himself in a series of low-paying, often back-breaking jobs. He recently decided to get his degree when he had his first child and wanted to start building a better life. Tucked away in an industrial park in Tempe, Rio Salado didn't look much like a traditional institute of higher education. There were no students running to class. Just a couple of glass-faced office buildings. The college had just 22 full-time faculty serving 60,000 students, with more than half of them attending classes online. Several students I met during my visit said they liked learning online. "I've taken college classes in a big auditorium with herds of people. There was no personal connection," one student said. "Now I can reach my teacher with the click of a mouse." After several days' visit, I left Arizona feeling quite optimistic about what the future holds for higher education. What is the writer's purpose by writing this passage?
To explain what "colleges without walls" are. To advertise the colleges. To encourage people to attend higher education. To introduce a new model of education.