# What type of sampling is this?

I have some confusion about the kind of sampling I'm using. I started by choosing the manufacturing sector and within it, chose 4 industries. Later I distributed questionnaires within those 4 industries as per my convenience (convenience sampling).

What kind of sampling am I using?

## 1 Answer

Convenience sampling (an instance of non-probabilistic sampling). You might call it multi-stage convenience sampling.

If you used convenience sampling to choose the experimental units in each industry, your sampling scheme is convenience sampling. Even if you chose the manufacturing sector randomly, it remains convenience sampling. Even if you chose the industries randomly it remains convenience sampling. If the latter two are also convenience sampled it naturally stays convenience sampled (here you might say it is a combination of convenience and purposive sampling).

Bottom line is you can't get the convenience out of your sample.

• Thanks Momo for your reply. I was thinking that it may be quota sampling. I was reading the book by Joseph Hair (2007) and felt my sampling method is quota sampling? – Muzi Jun 21 '12 at 7:41
• In my understanding, the distinguishing feature of quota sampling is that you segment your population somehow and that you sample from each segment a certain proportion. Imagine you stratify the population based on age groups and from each age group you sample 400 females and 100 males. From your description you made the stratification, then chose a subset of the strata and then in each stratum convenience sampled (but not proportion based). Yours seems to be the non-probabilistic equivalent of multi-stage cluster sampling. – Momo Jun 21 '12 at 8:28
• Quota sampling is not any good, anyway. There must be a probability element leading to selection of your units, and if there isn't any, it may be a great sample to study the phenomenon qualitatively, but there is no way to generalize it to any other population or its subgroup. – StasK Jun 21 '12 at 14:09