We don't use flat templates in Alpha. We use a full context-free grammar that turns the question into a symbolic representation of what the user wants, which can naturally involve chaining. E.g. "when was the president of the US was born".
Then we execute that symbolic representation using a variety of strategies. There are funnily enough quite a few cases where we can understand the question but don't have the curated algorithms to actually answer it.
"How tall [object]?" / "[object] height"
"Becoming a [job]"
"How much is a [unit] of [object]?"
"How old is [object]"
"When is the next [event]"
My question is: Do Siri/Cortana/GoogleNow use such flat templates (per topic) or do the use an IR ontology? http://en.wikipedia.org/wiki/Ontology_(information_science)