Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good auxiliary training; no longer referenced by FAA PTS

A good, reasonably comprehensive training manual, easy to read. More modern, less technical than American Soaring Handbook (out of print). For many years Joy of S. was the primary basis for FAA Glider Pilot Certificate testing, and I issued hundreds of certificates based on it; now superceded in Practical Test Standards by a different book of slightly inferior quality (Jeppesen).