Hotel research company Smith Travel Research classifies hotel chains into market segments by average rate. You can see the details here. Their scale segments (for chain hotels) are currently Economy, Midscale, Upper Midscale, Upscale, Upper Upscale, and Luxury.

This is where they put Marriott's brands (sorted alphabetically within each segment):

• Luxury: Bulgari, Edition, JW Marriott, Ritz-Carlton
• Upper Upscale: Autograph Collection, Marriott, Marriott Conference Center, Marriott Executive Apartments, Renaissance
• Upscale: AC Hotel by Marriott, Courtyard, Residence Inn, Springhill Suites
• Upper Midscale: Fairfield Inn, TownePlace Suites

Marriott collects hotels with flexibility in brand standards in the Autograph Collection. For example, some (but not all) of the US Autograph Collection hotels are part of Kessler Collection (which has issues).