Anticipation is often worse than the actual experience, which seems to hold particularly true for both the PHR and SPHR exam day. Here's a quick overview.
Looking at the exams' structure and types of questions
Both exams have questions that are written by certified HR professionals, not academics. HRCI correlates exam scores to the years of experience that are required for the tests, which is in part to justify the need for practical work experience for a successful test. Furthermore, as part of the accreditation process, the exam content is validated to the exam bodies of knowledge (BOK). The exam's BOK are based on an analysis of the HR field as a whole. Test questions are written to the exam specifications to validate the relevance of each question.
Although all test items are multiple choice with four possible options, each question may be worded differently. The exams include scenario, direct, and fill-in-the-blank questions.
Grasping how the exams are scored
Many test takers are really only concerned with passing or failing, which is fine. Students must have a total scaled score of 500 to pass these exams.
However, the exams have two types of scores that affect what you need to pass:
Raw: The raw score is the actual number of items answered correctly on your test.
Scaled: The scaled score represents the difficulty level of the random exam you received.
There are thousands of PHR and SPHR test questions. You only have to answer 175 of them. You may receive 175 of the questions that are rated as difficult whereas the person next to you may receive 175 of the fairly easy ones. That means that you'll be allowed some wiggle room while still needing to achieve the scaled score of 500 in order to pass. It's an exercise in fairness.
Don't leave a question unanswered. Scoring is based on the number of correct answers, so leaving an item blank — even if it's an educated guess — eliminates the possibility of that item counting in your scaled score.