I am also curious about this! Thanks for asking!

I have them read for 1 minute.  If they're not able to read a word within 3 seconds, I tell them the word and mark it incorrect.  At the end of the minute, if they were 90% accurate (with however many words they read), I move them on to the next skill.

Thanks for the response,Patty. I agree with you. 1 minute reading for a skill measure and move students on with 90% accuracy.

What if the student has read just 7 words with 90% accuracy, in one minute?  If you suggest I use my professional judgment,  we are now turning a very black and white system gray. 

 We recommend that schools use the 90% accuracy point as a guideline for determining when to move on in the phonics skills. Automaticity (fluency) is a factor because of the 3-second rule. If you revisit the Skill Monitoring - Word List Directions page in the Assessment Manual, you will see the recommendations for scoring. If a student does not read a word within three seconds, the word is counted as an error. So, if a student isn't automatic when reading the words, the student would have low accuracy and would not be ready to move on to the next skill. When a student reaches 90% accuracy (when using the 3-second rule for each word), you should move on to the next skill. The student will still be working on reading with more automaticity in the next phonics skill as well.