Reddit mentions of Universal Methods of Design: 100 Ways to Research Complex Problems, Develop Innovative Ideas, and Design Effective Solutions

Interaction Design

• About Face 3 by Alan Cooper
  
• Designing Interactions by Bill Moggridge
  
• Designing Interfaces by Jenifer Tidwell
  
• Designing for the Digital Age by Kim Goodwin
  
• Making Things Talk: (2011) (2007) by Tom Igoe
  
  Interior Design
  
  
• The Decoration of Houses by Edith Wharton and Ogden, Jr. Codman
  
• Domino: The Book of Decorating by Deborah Needleman
  
• Design*Sponge at Home: A Guide to Inspiring Homes by Grace Bonney
  
• The Vintage/Modern Home by Katherine Sorrell
  
• The Fundamentals of Interior Design by Simon Dodsworth
  
  Landscape Architecture
  
  
• Landscape Architectural Graphic Standards by Leonard J. Hopper
  
• Landscape Design: A Cultural and Architectural History by Elizabeth Barlow Rogers
  
• Landscape Graphics by Grant W. Reid
  
• Cities for People by Jan Gehl
  
• Design with Nature by Ian L. McHarg
  
  Lighting Design
  
  
• Stage Lighting Design by Richard Pilbrow
  
• The Architecture of Natural Light by Henry Plummer
  
• Painting With Light by John Alton
  
• Made of Light by Anthony Tischhauser
  
• Color, Environment and Human Response by Frank H. Mahnke & Rudolf H. Mahnke
  
  Product Design
  
  
• Sketching: Drawing Techniques from Product Designers by Koos Eissen
  
• Design for the Real World by Victor Papanek
  
• The Craftsman by Richard Sennett
  
• Mythologies by Roland Barthes
  
• Cradle to Cradle. Remaking the Way We Make Things by William McDonough & Michael Braungart
  
  Product Design
  
  
• In the Bubble: Designing in a Complex World by John Thackara
  
• The Experience Economy by B. Joseph Pine II & James H. Gilmore
  
• Universal Methods of Design by Bruce Hanington & Bella Martin
  
• Cradle to Cradle. Remaking the Way We Make Things by William McDonough & Michael Braungart
  
• Mental Models by Indi Young
  
  Sound Design
  
  
• Sound Design: The Expressive Power of Music, Voice and Sound Effects in Cinema by David Sonnenschein
  
• Designing Sound by Andy Farnell
  
• Audio-Vision: Sound on Screen by Michel Chion
  
• The Sound Effects Bible by Ric Viers
  
• Sound Theory Sound Practice by Rick Altman
  
  Urban Design
  
  
• The Death and Life of Great American Cities by Jane Jacobs
  * Cities for People by Jan Gehl
  
• A Pattern Language by Christopher Alexander
  
• The Geography of Nowhere by James Howard Kunstler
  
• The Image of the City by Kevin Lynch
  
  Web Design
  
  
• Don't Make Me Think by Steve Krug
  
• HTML & CSS: Design and Build Web Sites by Jon Duckett
  
• The Principles of Beautiful Web Design by Jason Beaird
  
• Responsive Web Design with HTML5 and CSS by Ben Frain
  
• Hardboiled Web Design by Andy Clarke
  

Check this out:
https://www.amazon.com/Universal-Methods-Design-Innovative-Effective/dp/1592537561

You should get this book instead and practice doing usability tests, interviews, field studies and different workshops https://www.amazon.com/Universal-Methods-Design-Innovative-Effective/dp/1592537561

There are several levels of playtesting formality, and that will depend entirely on your access to resources. Something that will probably never change is that you have to start playtesting in-house before opening it up for public, because most systems are too raw when starting up. Public testing also serves a double purpose of collecting feedback and building an audience at the same time, if you're lucky and do it correctly.

About coming up with important question when going public, or even when observing your own players, I have a few caveats:

• Observing people during play is often better than asking them what they thought. Most people do not know what they want until they get it or are enough of design nerds to concretely understand and express why something rubbed them wrong. If you can have a friend run the game for other friends and be present as an observer taking notes, you might learn more than asking directly. Running the game yourself is, of course, an option, but it comes with the troubles of multitasking;
  
• "Did you like it?" are good question for encouragement, but not that good for playtesting (unless the majority of answers are "No"; then you have a great indicator). Try to ask more objective questions like how did players feel at certain points in combat, if there was a feeling of getting stuck at any point during play, &c.
  
• While quantitative research is great for some metrics and finding new problems to solve, it sucks for finding solutions. When you're in doubt, opt for qualitative.
  
  Universal Methods of Design is a great book overall and explains lots of tools used in every part of a design workflow, and a lot of them are intended for product testing, if you're interested on some harder reading.