It's easy to scoff at the work--and the worry--psychologist Shapiro and psychiatrist Tuckman build into taking a vacation, but aside from providing a textbook for those proliferating Leisure Science courses, their effort could help vacationers avoid two costly weeks in the dumps. Choose the type of vacation that suits your temperament and needs, they advise, taking up the pros and cons of holidays devoted to self-improvement, rest and relaxation (but: too much r & r can be tiring), roughing it, imbibing culture, seeking sex, hunting bargains, searching out roots. Don't let a travel agent dictate your trip, they warn, and if others are going along, decide ""who wants what and when they want it."" And, especially, beware of ""spoilers""--those unresolved anxieties (guilt, fear of losing control, etc.) or tensions that can sabotage the best-laid plans. A sensible counter-agent to the glossy brochures.