You plan a pair-work speaking activity. It looks simple: give students a role play card, they practise, then share with the class.

On paper, the steps are clear. In practice? One pair chats in L1, another races through the task in two minutes, one group spends the whole time debating a single word, and another invents an entirely new dialogue that makes the class laugh.

Same task, different outcomes. That’s complexity.

Complexity theory looks at systems (like classrooms) ...