This document discusses both the promises and limitations of using big data analytics to predict job performance. While big data can provide insights, the metrics used may not capture all important factors, and algorithms can make flawed assumptions. Personality tests alone cannot determine who will succeed in a role, and a manager focusing only on short-term targets may hurt the organization long-term. The strongest evaluations come from people familiar with an individual's past performance and behavior over time. Managers should consider statistical analysis carefully alongside other factors to avoid uncertainty and make effective decisions.