Work sample tests are designed to closely resemble actual job tasks to have high validity. They require examinees to perform realistic job simulations. Advantages include high reliability, validity from matching real work, and reduced bias. Disadvantages include high costs as most can only test one person at a time, and inability to predict long-term performance. Different types include trainability tests, simulations, and low-fidelity replicas. Validity is established through content validity by matching test tasks to job duties, and criterion validity by correlating test scores to job performance ratings or production measures.