hippo2002,
you are right. they read by memory. in a way, it is good to check on tonation/pronuncation. the good thing about the orange booklet system is that they will repeat some of the common words in the subsequent few booklets.
for me, to rectify the 'read by memory', i will randomly write those 'new' words on a piece of paper to test my boy. if he can't read them, for the rest of the week, i will paste them on the fridge and revised with him (the standalone words, not in a sentence)- a few minutes a day...he usually gets it by end of the week. then i transfer them to a booklet in random order. then at the end of a few weeks, or whenever i am free, i will choose random words to test him.
so using the orange booklet and the white sheets of paper, i can usually come up with some words he can't read, and add some more similar words (eg similar strokes or related words (totalling up to abt 5-8 words) and use that to teach him for the rest of the week.
we have to do the reinforcing...cos berries alone is only once a week nia...