Epidemiologists use critical thinking at various stages of their work: 1. Formulating Hypotheses: Critical thinking helps in developing plausible hypotheses based on existing knowledge and observations. 2. Data Collection: It guides the selection of appropriate methods for data collection to ensure accuracy and reliability. 3. Data Analysis: Analyzing complex data sets requires identifying patterns, correlations, and potential causative factors without jumping to conclusions. 4. Interpreting Results: Understanding the limitations of studies and the potential for bias is critical for accurate interpretation of results.