Simon's bang on with this.
The technical aspects of a photograph are useful to note, but are secondary in many respects.
It's like Potter Stewart's definition of porn "I know it when I see it". Several images will jump out at you and the judging panel. Choose those irrespective of whether they adhere to notional standards of what is or is not a good photograph. Failing that, look for the ones that seem to suggest a back-story or that express the life the subject or the photographer leads.
Ultimately, photographic education adds consistency and meaning to the lucky happy snap moments, and because these newcomer photographers will lack some of that consistency and not have their visual language so clearly defined as yet, you may well be looking for potential as much as actual skill.
Plus, there's nothing better that to say to someone they 'have potential...'