PROBE is a "running record" reading comprehension test. It is administered individually to students, and enables teacher to monitor both the fluency with which a text is read, and the degree to which the student has understood what has been read. Students read the text aloud, whilst the teacher makes notes, and then answer questions designed to assess a range of comprehension strategies.

The tests are graded by "reading age", and are passed when students achieve either 90-95% accuracy  when decoding words (with at least 80% comprehension of what has been read),  or  95-100% accuracy when decoding words (with less than 80% comprehension).  Progress is cumulative, but students can spend some time consolidating their reading comprehension within one reading age range before they are ready to move on to the next level.  

When students are considered to be reading fluently in the senior school, PROBE is used on a needs-basis.