Question about Approval Ratings... GLP can you help me?

As approval ratings ebb and flow, there is definite mention of it in all nightly newscasts. All I was wondering is if anyone knew how this information was gathered. Who exactly do they see fit to poll in order to determine the emotion of the entire country? And by golly I feel cheated. No one ever asks me what I feel about recent presidential decisions. Why was not my input included? Can anyone out there in Never Neverland explain it to me?