The reader substitutes words that look similar to the actual word in the text; poor for pool, better for belt. If the reader substitutes words that look similar, she/he is most likely not reading for meaning. The reader could be reading too fast, struggling to decode words, or just reading to complete a task.
With each type of miscue, if the reader does not re-read the text and self-correct errors, she/he is most likely not reading for meaning or is not fully comprehending the text