The Gallup poll on Egypt after Jan25 doesn't mention if the selection of face-to-face interviewees involved any form of randomisation. Yet, the American sample involved random digit dialling.

Information on the methods used is inadequate. We can't say the sample interviewed was representative and results generalisable without more information.

I hope they will publish something in the next few days with more details regarding the methodology.

Link: Egypt From Tahrir to Transition