Question 377281
First of all you would like to formulate your hypothesis for a specific region, age or another characteristic that will reduce the data, 
like if you want to know the attitude of students studying clinical psychology toward psychoanalytic methods of psychotherapy, you would like to describe them a bit more as in in the university XYZ or in the area UVX,
Then you need to make questionnaires, like 5 points or 7 points likert scale, next when you have a question ire and the area in mind, you will do either simple random sampling or stratified sampling on the basis of how many years they have studied psychology so far.

The limitations would be that attitude is subjective, each one has a different state of mind when filling the question sheet so mood or the need of being discrete introduces a bias in the data.
HTH