Group chats can get annoying real quick if the people in them are sending rapid-fire texts without hesitation, especially if none of them are any interest to you specifically. Luckily, it's easy to mute notifications for specific message threads. You can even leave a group chat if everyone is using iMessages, but that could lead to you missing an important message.
There is another option, though, specifically for the Messages app in Mac OS X Yosemite, that alerts you whenever your name is actually mentioned in a group conversation. Whether someone uses your first or full name, you'll receive an alert saying that you've been mentioned, making it easy to check up on the messages most relevant to you—instead of all of them.
On your Mac, open the Messages app, go to the menu bar, and click on Preferences. In the General section, check the box next to "Notify me when my name is mentioned."
Now whenever your first or full name is mentioned in an iMessage, you'll receive a notification like the one in the screenshot below. You'll also hear a notification sound instead of the regular ping you're accustomed to when receiving an iMessage.
The next time you see a group chat show up on your computer, don't groan—Mac OS X will make sure to notify you when it matters.