Do gerunds need a noun after them?

Question

I wrote this sentence

Today, there is a trend toward using document understanding and spatial reasoning [Methods ?] for capturing the conceptual structure of a web page.

Is "methods" necessary?

Answer 1

Briefly, no: a gerund is a participle which acts as a noun, and it supplies all the "nominality" required.

Note, by the way, that if you're going to use that many gerunds, you would do better to make your final clause an infinitival:

Today, there is a trend toward using document understanding and spatial reasoning to capture the conceptual structure of a web page.

Most languages dislike repeated use of grammatically similar constructions too close together—grammarians call this horror aequi.