22 January 2013 8 Comments
There are lots of different sorts of sampling techniques (both random and non-random) and a myriad of books that explain the best one to use for any given methodology. ‘Snowball sampling‘ is my favourite – you start with one person and ‘sample’ them, then you ask them who you should talk to next, and so on. I like the convenience (when it is used well), and I love the name.
It seems to me that lots of people use a technique that I don’t like at all.
Let’s call it “Lazy sampling”.
“Participants in the study were 35 undergraduate students (24 women, 11 men) aged 18 to 26, recruited from a large university in [the area where the authors work]. We recruited participants in the [sociology] lab at the main campus and many received extra credit in their courses for participating in the study.”
[Information obscured so as not to embarrass the authors]
Just to be clear – this was not an educational research paper. It wasn’t talking about pedagogy or course development. It wasn’t a study about tertiary education. They were looking at a general social issue, using university students as their sample.
In selecting their sample, the researchers made the following decisions:
- They drew their sample from the University where they work, or (at best) a university nearby.
- They drew their sample from one laboratory on one campus.
- They either constrained the age of their sample so that only students would be selected, or they defined their age range after they had seen the ages of the students.
- They either constrained their sample to students or they worked within a reward structure that resulted in only students applying. No admin staff, no faculty staff, no visitors to the laboratory…
- They either didn’t care about gender or they didn’t try to recruit for even numbers.
Why? Why would anybody constrain their sample so tightly? One laboratory – what is that about ? Why would anyone exclude staff or visitors to the university? As a researcher, why wouldn’t you step outside the university and recruit from the local town or city? Wouldn’t it make your study stronger? Any expansion of the sample would have made this paper more interesting.
I don’t like this lazy sampling. I don’t like it at all. It really disappoints me when I open a promising article, only to find that the sample was this small and constrained.
Putting aside my own personal disappointment, lazy sampling is poor research.