I'm looking for a phrase - GOT IT, THANKS!

[sid]

Help me if you can!  I've read a phrase that I can't quite bring to the tip of my typing fingers.  It means, roughly, to jump to conclusions, and it goes, roughly: something-ing ahead of your data.

Ring any bells for anyone?  :-)

Comments

[bluflamingo]

theorising ahead of your data? I think that's the only version I've ever heard, usually mildly sarcastically.

[sid]

OOH, I think that's it! Thank you! :-)