Which one is commonly use/ appropriate use for Urban and regional planning research?

(ask me why when we are in synchronous mode)

When you don't know the area nor have the preliminary information about area or people that you want to research, what kind of sample that you can use ?

When you know there are a lot of type of community to represent the information you need, what kind of sampling that you want to use ?

What are the common use of convenience sampling?

Ask the experts are typical for 

Why we need sampling quantitative research?

What is the main differences between simple random sampling dan systematic random sampling?

In quantitative sampling there are also non probabilistic sampling, this has meaning that..

There are similarity between non probabilistic sampling and also qualitative sampling, are they different from each other?

What are the differences between the quantitative random sampling and qualitative random sampling?