When I first read this article, all I could think about was the classic 1996 movie Biodome, and the oh-so-horribly-spectacular Biodome 2. I mean, with a headline like "Scientists Emerge From Dome After 8-Month Stay to Test Life on Mars," I'm only going to be able to think about Bio Dome!
In reality, though, these scientists were looking to do something a litttttle more professional (and in a smaller space!) They were in isolation for 8 months on a mountainside in Hawaii, where they only had 6 minute showers every week and only left the dome occasionally in space suits to simulate what it would be like to be on Mars. From their portal window, they couldn't see anything but lava fields.
The goal? To study how team work and cooperation in such a space would work: "Tracking the crew members' emotions and performance in the isolated environment could help ground crews during future missions to determine if a crew member is becoming depressed or if the team is having communication problems."
While this wasn't the real deal, I can't imagine how annoying and difficult it would have been to spend 8 months in such a small space with six other people!