A teacher asks her learners to collect words / phrases on various aspects they…

Thematic vocabulary learning is a vocabulary-teaching approach in which words and phrases are grouped and taught around a shared real-world theme or context (for example: market, kitchen, weather, transport) instead of being learned alphabetically or as isolated, unconnected items. Organising new words around a common context builds a network of related meanings and ties vocabulary to lived experience, which supports longer retention.

In this activity, learners are sent out to observe and collect words and phrases from a real, lived context — their local markets and streets. Back in the classroom they sort what they collected according to category and discuss it together. Collecting vocabulary from a real environment and then organising it by shared theme is exactly the collect-categorise-discuss sequence that defines this technique.

• Genre based words classifies language by the form or type of text (a story, a report, an advertisement, a poem) rather than by the real-world subject the words come from, so it does not match an activity built around observing markets and streets.

• Active vocabulary is a level of word knowledge — the words a learner can produce spontaneously in speech or writing — not a name for a technique of collecting and sorting words from the environment.

• Topic words learning is an everyday phrase, not an established term in language-teaching methodology for this specific environment-based, category-driven word-collection activity.

So the practice described — collecting words/phrases from a real context and organising them by category — is what is called thematic vocabulary learning.