Tim Gunn is chief creative officer at Liz Claiborne Inc. and co-host of Lifetime TV’s “Project Runway.” He delivered the keynote address at the Cooper-Hewitt, National Design Museum’s Teen Design Fair in October. He spoke with the magazine’s Megan Gambino.

How do you recognize good design?

It’s largely visceral, to be perfectly honest. If my brain tells me that a new design should resonate with me, but I’m unmoved, then I always go with my gut. I was talking to faculty members at the Parsons School for Design, where I taught for 24 years. They were telling me about how they initially evaluate a new object. They come upon it not really looking at it. They see it in the periphery of their vision and then they look at it for a split second and close their eyes. It’s that moment of reckoning that tells them the value of the object.

Your mantra on “Project Runway” is “Make it work.” What does that mean exactly?

“Make it work” was born in my classrooms. It came from teaching students who, in the course of working through a particular project, were unhappy with how it was evolving. They were inclined to abandon the entire effort and start again from scratch. I would never let them do that. I would say, let’s study this. You study it, you bring your own critical analysis and objectivity to it, offer up a diagnosis of what’s wrong with it and then offer a prescription for how to make it work. Doing so provides the individual with a whole set of resources to draw upon when moving forward to the next project. It’s about problem solving. And it’s a skill that’s not just applied to design projects, but to how we navigate life.

What impact has “Project Runway” had on the fashion world?

Initially, the show was very polarizing in the fashion industry. The designers responded well to it. They thought, my family who doesn’t really understand all this can say, “Oh my God, is this what you go through?” The fashion magazine editors felt different. They were very invested in the mystique that enshrouded the fashion world. “Project Runway” ripped the veil off and said, here, look at it. It’s gritty. It’s daunting. It’s dirty.

You’ve said that design is a barometer gauge of what’s happening in our society. How so?

Designers, I believe, on one hand, see themselves as just that: designers. But when they are in fashion, I believe they also see themselves as being sociologists in a way. Their work is emblematic of a particular time and place. I certainly don’t want to imply that you could take an article of clothing or a furniture design or a work of architecture and say this defines America in the Obama era. But that item or that object or that building is an atom or a molecule that’s extracted from the larger structure of society and culture. In some ways, it is easier to reflect on it than it is to either predict it or describe it in the here and now, which is certainly what fashion historians tend to do.

In what ways can a visit to a museum be beneficial to a designer?

First of all, it’s inspiration. Secondly, it gives you a broader view of your place in the world. When I was last at the Smithsonian’s National Museum of American History, just seeing the new installation of the Fort McHenry flag was just absolutely awe-inspiring. I thought, what a great point of departure for a whole fashion project. I’m always saying to my students you need to know the national and international news, even the local news. You need to know what movies people are going to see. You need to know what books they are reading and downloading, what music they are listening to, what music videos they are seeing. Read everything, and look at everything. Then use your own filter to edit out what’s either relevant to you or not relevant to you. Have these things as part of your being, part of your everyday navigation of the world.

What problem would you most like this next generation of designers to solve?

Women who are larger than a size 12 are a very dismissed population. I feel that designers are thumbing their noses at these individuals, and it’s done disrespectfully, without any real concern for the challenges of dressing a larger woman. I have to say I am really intent, speaking for my day job at Liz Claiborne Inc., on having our Liz Claiborne brand address this, and get it right.

What current teenage fashion trend irks you the most?

Too much skin; especially bare midriffs. I find it distasteful. And I tell them so. Clothes are a form of semiotics. They send a message, and it’s important to accept responsibility for that.