How media houses gather information about the popularity of a certain television progam?

A media house wishes to gain information on the popularity of certain television programmes. There is a plan to use interviews to gather information. What are THREE methods the media house could use to conduct the interviews? Which other method, other than the interviews, that the media house could use to gather information?|||I only know one way for sure. A couple times in my life, I've been selected by mail to keep track of what programs my family watches by writing the names and times down in a little booklet they've sent, and sending it back to them with pre-postage paid envelopes. Occasionally, a one dollar bill would be in the envelope with whatever booklet or encouragement they were sending me. I made between three and five dollars both times. And I felt very special and priveledged to be doing it (the first time I was probably like 11, so yeah).