So you're given the altogether grueling, Herculean task of evaluating the world's best hotels. Fragile orchids float through lobbies, delicacies tease the tongue at Michelin-anointed restaurants, infinity pools evaporate into the blue horizon, spas dazzle both body and spirit. Webster defines luxury as "something adding to pleasure or comfort but not absolutely necessary." How to possibly measure the immeasurable? Ultimately, luxury is an experience of the senses. Hotel guests are immersed in the radiant colors of furnishings, the perfect aesthetics of architectural design, the softness of fabrics, the sensations of comfort and warmth, the fragrances that infuse the air. But beyond this, the true luxury hotels are distinguished by their service, and their uncanny eye for detail. There are many places that boast sumptuous surroundings, but true luxury hotels cater to your every (perhaps childish) whim and desire: particular desires and even some you haven't even thought of yet. And they fulfill those requests with savvy and graceful style. But beyond this, how can one assess this luxury experience? Five Star Alliance travel agency has established a concrete framework by which they examine new hotel properties to add to their comprehensive, handpicked directory. Hotels are assessed by the following tangible criteria: 1. The industry awards (a.k.a. let the other guys work for you). Conde Nast Traveler's Gold List, Travel and Leisure's Top 500, Mobil 5 star, AAA 5 diamonds. 2. Hotels that are part of renowned brands, like Ritz-Carlton, Rocco Forte, Four Seasons, Shangri-La, Fairmont, Mandarin-Oriental, Oberoi, Peninsula, Relais and Chateau. 3. Other categories or brands: Small Luxury Hotels, Luxury Collection, Leading Hotels of the World, American Express Guide, Robb Report, Andrew Harper's Hideaway Report. 4. Significant references: in the press, word-of-mouth, and personal experience. 5. Facts and figures. Sometimes the rates say it all. If a hotel charges less than $150 per night, one can safely assume that it is not of a certain caliber. These criteria provide the matrix, but not the automatic or guaranteed endorsement. For example, Leading Hotels of the World boasts a collection of many superior properties, but a hotel's affiliation with LHW does not signify obligatory inclusion on the Five Star site. So, readers, help us define, like Webster, the meaning of "luxury"; let us know about luxury properties you recommend. Even the sharp eyes of Five Star Alliance editors may have missed something! In the future, Five Star Alliance hopes to provide a feedback tool directly on the website, where travelers can share their own perceptions about a luxury property. For luxury, like beauty, must ultimately be in the eye of the beholder.