Four things go up in a two-by-two grid — snippets, devices, apps, error messages, anything — and the question is always the same: which one doesn’t belong? There is no answer key. Every corner can be defended, and the defence is the point: arguing a corner out loud forces the precise vocabulary that vague pointing lets you avoid.
How to run it
- Show the grid. One quiet minute — everyone picks a corner.
- Hands up by corner. Every corner should have takers.
- Defenders speak. The rule: name the property, not the vibe — “it’s the only one that stores text” beats “it looks weird”.
- Close by collecting the vocabulary the defences used.
A grid to start with (click to expand)
count"count"3count = 3Only a name. Only text. Only a number. Only a complete statement that does something. Four corners, four defensible claims — and four words from Data in Programs worth owning.
One variation
Students build the grids. A good grid needs four properties that overlap three ways each — building one beats solving ten.
Argue the corner you did not pick
Once your corner is safe, defend a different one. Being able to argue all four positions is what owning the vocabulary means.
Curriculum connection
C1.1
use appropriate terminology to describe programming concepts and algorithms
Link to original