This activity shows the importance of sampling methods and how sample is just a subselect of a population and how different methods might affect the results in unpredictable or predictable (biased way).
You will need either a bunch of poker chips of varied denominations or some marbles, papers with printed numbers etc. You also need sachets, bags or cups which will serve as a draw bags for the chips for the students. The good chip numebrs to choose can be either normal chip denominations, or better to tie it to another psychological scale, such as Extraversion T-score, or memory span etc.
Create several “groups” of 7 chips which will have different expected average value but with different “variables”. The values below are from a range of 1-10 with different average expectation in each group and expectation of 5.4 overall.
| Group | Description | Average value | Values |
|---|---|---|---|
| Normal | Normal population with a normal non extreme spread | 5 | 3,3,4,5,6,7,7 |
| Normal shifted | Normal population with the same SD, but mean is 7 | 7 | 5,5,6,7,8,9,9 |
| Extremes | the sample has average the same as normal group but with many extremes | 5 | 0,0,2,5,8,10,10 |
| Bias side | Sample has only few extremes but oly on a single side | 0,0,4,5,6,7,7 | |
| Unreliable | Has same numbers as normal population, but some values are missing | 3,missing,4,5,missing,7,missing |
To demonstrate opportunistic sampling, explain that each bag is a school of kids and have each group sample only that, which is closes to them.
| Name | URL |
|---|---|
| Randomisation of possible outcomes | https://github.com/hejtmy/porgR/blob/master/sampling/sampling-poker.md |