I was taught GCS and AOx4/AVPU scale.
What drives me bonkers more than anything is that AVPU and AOxwhatever are taught as separate assessments, and they aren't. You first determine if the pt is Alert, or responds to verbal stimuli, or painful or unresponsive. If you find them alert you then use the questions to determine how alert. Telling someone a patient is "Alert" doesn't tell me anything more than their eyes are open.
/rant
In most cases I start with "Hello my name is xxxx I'm a paramedic with the ambulance, what is your name?" If they can tell me, then I ask "What is going on today?" or some version of. If they can't tell me, then I ask them if they know where they are. If they get that one, I ask if they know the date.
I will also ask them to hold out one hand or the other so I can take a pulse. It's an easy way to assess if the pt can follow directions.
I usually end up asking a lot more than 4 questions with patients who don't answer one right. For example, if they don't know the date, I'll ask them the day of the week, then the month, then the year and see if they know those. If they don't know what building they are in (home, work, the grocery store etc) I will ask them if they know what city they are in.
A lot of times when we pick up homeless/transient patients they won't know the day of the week, but they will know the month and year. For them that may be totally normal. I also work nights, so at 1am a pt will answer Tuesday, when it's really Wednesday now. It doesn't mean they are altered, so you have to be able to assess the pt outside of the questions.