What are the differences between Situational Language Teaching, Direct Method and Audio-Lingual Method?

Identifying differences can sometimes begin with clarifying similarities. A similarity
between the
Situational Language Teaching, which began in the 1930s, and the href="https://www.sil.org/resources/publications/entry/67412">audio-lingual
method, which began in the 1950s, is that they both use Structuralism as the
foundation for language learning practices.

In contrast, the href="http://www.teachingenglish.org.uk/article/direct-method">direct teaching
method, which was developed in 1900, does not use Structuralism as the foundation for
language learning practices. It was instead a response to the Grammar-Translation (translation
from one language to the other) method of language teaching.

Since the
situational and the
audio-lingual methods are linked to Structuralism, they both rely on
behavioralism and emphasize habit-formation, correctness, and contextual and cultural clues. One
way these...