I feel the PAL-1 Open Assessments do not accurately reflect the Certification test. I took the Open Assessments a couple of times, both to see what the test felt like and as a "warm up" to the actual exam. Imagine my surprise when they were nothing alike, although I did pass the first time.
Almost all (if not all) of the Open Assessment questions are True/False on short statements. Almost all (if not all) of the Certification questions are "Choose the Best" from several choices -- many in "story problem" format.