Textual intervention is a complex notion. I'll try to explain it from my pov as it really deserves being discussed.

Textual intervention is the process of making various theories of using literature in ELT that actually is based on ss' activity & creativity while reading. It may involve some intertextual component, the usage of media, elements of visual art. It's an attempt to incorporate existent (and sometimes provocative at first sight) knowledge,to  abstract from it and look at this process from a different perspective   at the same time.

Imitation can be used through the activities applying body language (e.g. Mime the story/dialog). I've seen such examples and they really encourage some imagination as sometimes they help understand the inner world of different characters better.

As for parody it may be challenging  to considerate the text not as a complete, stable construction but to reconstruct it somehow. Rob Pope calls this "re-writing"in his Textual Intervention (1995): it enables the usage of different linguistic competences in changing conditions.  Raymond Queneau in his Exercices de style (1947) introduced 99 variations of one story (different in genre, style, etc.)

http://fr.wikipedia.org/wiki/Exercices_de_style

These complex approach can be formulated in a simple task like Rewrite the story as it were a detective story/a love story, etc. It's really thought-provoking and encourages ss' creativity. It's an element of the BritLit project (which you can get to know with in my posts).

Dear colleagues, have you ever used techniques like these in your teaching practice? 

PS: it was originally supposed as an answer to Anna_Leshchenko's comment here but evolved into a separate post. The 1st part may be traced here:

http://www.teachingenglish.org.uk/blogs/mike-le-prof/it-possible-play-te...