Can you act them out with you being the researcher and using the class as your population? If you come up with a silly / trivial research 'topic' it could be quite humorous and harmless but memorable.

For example: Investigating doctoral students' attitudes towards chocolate.

PURPOSIVE SAMPLING: Pick someone without much thought (e.g. front row?) and ask what they think about chocolate. Record on the board / flipchart (summarise with a word or phrase e.g. 'love it' / 'enjoy' etc). Ask someone else - record again - if another positive, record nearby (with another keyword or just a tick etc beside the first one). Keep asking people, sort of 'quick fire'. Loosely group/sort responses as you place them on the board (this is illustrating - simply - how you are analysing the data as you go and noticing what you are getting). I can imagine you might get quite a lot of people saying 'love it' and maybe some saying 'hmm, it's okay but not my favourite' etc ... after collecting a number of responses you can look at the balance / coverage and say something like, "Okay, lots of positive and neutral responses here ... I don't really need any more of those ... is there anyone here who *doesn't* like chocolate?". This illustrates how you analyse the sample and then deliberately seek further respondents who might offer something different / check to see if there are any contradictory cases etc out there.

CASE STUDY: Start again. Pick one or two people. Sit them on chairs at the front and have a longer conversation with them about chocolate. When did they first experience it? What does it mean to them? Who introduced them to chocolate? Explore their preferences within the general category of chocolate ... etc. Illustrates the small sample size but greater depth.

SATURATION: Start again. Ask someone where they get their chocolate from. Record on board (e.g. supermarket, service station ...). Keep asking as in purposive example above but at the appropriate time say "Okay, you're all telling me places I've already got here. I'm not going to bother asking anyone else. I think we must have covered it." 

QUOTA SAMPLING: Say, "Okay, I need three people who love chocolate deeply, three people who can 'take it or leave it', and three people who really don't like chocolate." Assemble the group of volunteers ... they are your 'sample'. Illustrates the balance between pre-determined categories of interest, but you can show by just looking at the 9 people how the sample group may not be 'representative' of the whole class in other ways e.g. gender, age etc.

SNOWBALL SAMPLING: Put a numbered list of the class's names (first names only) on the board - if a large class, print this ahead of time to stick up!! Otherwise just quickly write their names down. Say, "I'm working on my sampling - I've already asked you all, so I've interviewed XX (number of students in class) doctoral students but I really need YY  (some bigger number) doctoral students in my sample. Do any of you know anyone else who is a doctoral student? Can you put me in touch with them?" Students will give names (first names only for the purpose of the exercise) of friends / people they have met who are also doctoral students but not in this class. Illustrates the idea of using people within your existing sample to put you in touch with other potential participants who fit your criteria (in this case doctoral students).

Of course at the end of this type of activity you can reflect on the challenges of each strategy.

I did a training recently. Take a look at the report. Perhaps you have done so already. You may get one or two ideas from the links inside it.

Thank you for these wonderful ideas. I will definitely try the chocolate exercise.  It will get the students talking and learning about the concepts of sampling. 

I was not able to locate a report R. N. Uchem. Can you send the link?

Sorry, Lewis. Here it is:

https://www.researchgate.net/profile/R_Uchem

RU.

Sorry, Lewis. Here it is:

https://www.researchgate.net/profile/R_Uchem

RU.

https://www.researchgate.net/profile/R_Uchem

Great ideas, Katrina.  Great question, Jordan!

I'm not sure why Katrina labels her first approach "purposive sampling" when it starts by picking "someone without much thought." Indeed just picking someone in the first row strikes me as the essence of "convenience sampling."

Purposive sampling would be something like: "Who has purchased some chocolate during the past week?" In other words, there would be some specific inclusion criteria.

I haven't done anything like this, but the concept you describe reminds me of the classic "who would you save" shipwreck exercise (https://rachelshae.wordpress.com/2010/10/22/who-would-you-save/) -- adapting that by asking students who they would choose may help them extrapolate the different ways sampling can be done.

Note: Excuse the informal link with somewhat harsh judgments revealed in the responses. 

 Good point, David L Morgan. Your way of starting off the purposive sampling is much better :)

I really like the idea, thank you for sharing

I found this question last night and tried Katrina's chocolate approach in a research methods course for research managers course today and it was fantastic for getting the students engaged. I ended up giving a bar of chocolate to a student who seemed to like it the most! So a big thanks to Katrina for answering the question and Jordan for asking it!

I structure small groups in which students receive information about a phenomenon-some of these scenarios I get from newspaper articles, or I write some of them. The small groups collaborate to structure a simulated qualitative inquiry that they then present to the class. Each group has a format to follow that begins with the rationale for the inquiry and ends with the Limitations of the study. I plan to include this idea and others in an edited book prospectus. If you have a unique idea that you think might fit in the prospectus, please contact me at [email protected]. (July, 2018)

I use Legos to teach about qualitative and quantitative methods.Anyone familiar with it? I'm looking for a few more activities as I'm looking for some new material.