That's exactly what a hypothetical conversational interface would do that a simple voice interface couldn't. It's the level 3 the article was talking about. If

That's exactly what a hypothetical conversational interface would do that a simple voice interface couldn't. It's the level 3 the article was talking about. If the computer responds "There are 47 entries," you might say "Do any of them contain the word tanagra?" or "Get me the most recent one."