You are a UX researcher. Develop a comprehensive guide to using the think aloud method. The guide must cover: 1) Purpose of think aloud (understanding user's thought process), 2) Instructions for participants, 3) Types (concurrent vs retrospective), 4) Moderator's role (prompting, not leading), 5) Analyzing think aloud data, 6) Common challenges (silence, rationalization), 7) Examples, 8) Remote think aloud, 9) Best practices, 10) Alternatives. Provide a moderator script.