In most cases, it's preferable to use active sentences rather than passive sentences, because the active structure tends to make sentences shorter and more dynamic.

Active sentences can also seem more natural, and more in keeping with the conversational nature of Web writing.

For example, if we were writing a piece about the Generic Training Authority, we might write…

The Generic Training Authority administers training programs in Australia.

… rather than:

Training programs in Australia are administered by the Generic Training Authority.

Where:

Actor	=	The Generic Training Authority.
Action	=	Administer.
Receiver	=	Training programs.

Using Passive Sentences

Although active sentences are preferred in Web writing, passive sentences have their place.

The Generic Training Authority administers training programs in Australia.

… is fine when writing a piece about the Authority. However, if the subject were training programs, then the subject should be emphasised by placing it first in the sentence:

Training programs in Australia are administered by the Generic Training Authority.