According to the Arizona Secretary of State’s signature verification guide, here are the things to consider in the 0-3 seconds you have per signature:
“ First step: Assess the broad characteristics of the signature. Extensive features include:
The type of writing (eg, cursive vs. printed) The speed of writing (eg, harmonic vs. slow and deliberate) Overall spacing General size and proportions Position of the signature (eg, slanted vs. straight) Spelling and punctuation If the broad signature characteristics of the ballot affidavit are clearly consistent with the broad characteristics of the voter’s signature in the voter registration database, you may accept signature and move on.
If not, go to step two. Step Two: Evaluate the signature’s local characteristics. If you find a combination of differences between the general features of the two signatures, evaluate the local features, which include:
Internal spacing The size or proportions of a letter or combination of letters Curves, loops and cross-dots The presence or absence of pencil lifts Leading and trailing strokes”