PILESGROVE, N.J.— Discerning buyers squeezed bundles of diabetic socks and scrutinized sweet potato cream cheese pies. Grown men reverted, unsheathing ninja swords while wives rolled eyeballs and shook their heads "No."

Some of the shoppers at the Cowtown Flea Market on Saturday breezed right past Eunji Kim, barely listening to her pitch beside the fried fish vendor. But others heard what Kim said — $10 for 10 minutes of their time inside a big box truck — and laughed out loud in disbelief.

"Yeah right. Yeah right," one man said.

Kim, 29, wasn't peddling the latest rain gutter technology or a state-of-the-art mop to cut cleaning time in half. She's a doctoral candidate at the University of Pennsylvania and had far larger, theoretical fish to fry inside the Institute for the Study of Citizens and Politics' Ford E350 Super Duty truck. Kim was paying customers at the iconic Salem County flea market to watch reality television clips, such shows as America's Got Talent and Shark Tank, and answer questions for her research into America's political culture and how media play a role in shaping and reinforcing it.

Jason Nark / Staff
Eunji Kim, a doctoral candidate at Penn, readies an iPad for her research into media and entertainment at Cowtown Flea Market.

Some of Kim's questions ask the respondents about their mood after the video. Do they feel "joyful, lively, proud, cheerful, or happy?"

Kim didn't want to disclose specifics of her thesis, but it may be no coincidence that America elected a reality television star as president in 2016.

"We have this idea, particularly among political scientists, that everyone's watching fake news and everyone is watching Fox News and that's why democracy is in collapse," Kim said beside the truck Saturday morning. "The elephant in the room is that Americans are watching so much more entertainment media today than they were 20 years ago."

The institute is part of the Annenberg School for Communication, and focuses on researching "public opinion, political psychology, and political communication," according to its web site. Professor Diana Mutz, the institute's director, said she created a mobile research lab that could venture out into rural and suburban areas because most volunteers on campus were overwhelmingly "liberal Democrats."

"You can't do good social science on one homogeneous group, so I felt like we needed to do something to bring more people into the lab or take the lab to them, which turns out to be a lot easier," Mutz, a political communication scholar who studies American voters, said at Penn last week.

The truck, which has two separate rooms with flat-screen televisions and chairs, has been to a blueberry festival in Bethlehem and the Quakertown Farmers Market. Kim polled nearly 150 people before Saturday morning's trip to Cowtown. Salem County is 81 percent white and Donald Trump took 55.6 of the vote there in 2016, one of nine counties he won in New Jersey.

"We really want to study everyone," Mutz said.

The truck was jointly purchased by Annenberg and Penn's School of Arts and Sciences. Kim and Mutz had to take an online class in order to operate the truck and said driving it is easier than it looks. Skeptics remain.

"I'm not gonna say nothing," said "Big Charlie," the parking guru at Cowtown.

After Kim backed perfectly into spot P-48, where a Chinese noodle food truck went up in flames last week, Big Charlie couldn't help but give her advice.

"You really ought to have your hazards on," he said.

Jason Nark / Staff
“Big Charlie,” a Cowtown flea market employee, talking to Eunji Kim after she parked Penn’s research truck Saturday.

Kim's father, who lives on a small island near the border of North and South Korea, also wonders about the truck.

"He saw these pictures of me standing by the truck and said, 'What exactly are you doing in the United States?'" she said.

Saturday started slow for Kim and assistant Anika Ranginani, 21, a Penn senior, with the first dozen passersby waving them off.

"I have to convince people it's not weird and creepy," Kim said.

Steadily, the duo began to rope people in, though, running from customer to customer as speakers from a nearby hair product vendor blasted hip hop. Kim was down to babysit a toddler or entertain a dog if someone agreed to get in the truck.

"All the babies will try to get to their mom, but that becomes noise in my data, so I'm like, 'Mommy is a little busy right now,'" Kim said.

Some wanted the $10 up front, but Kim was firm. Some just wanted to see the cash. One man held his bill up to the sun after the survey, still skeptical.

"I've got to take a survey and pay you $10," one woman asked Ranginani.

"No, we pay you," she replied.

"Oh, well, yeah, then, let's do it."

Jason Nark / Staff
Anika Ranginani and Eunji Kim help a volunteer with an iPad Saturday at Cowtown Flea Market in Salem County.

Kim said she usually gives herself a six-hour window at the flea markets, hoping to get 50 people for her research. By noon, at least 30 had gone into the truck at Cowtown or sat outside with an iPad, a good haul by her measure.

"I usually bring $600 with me," she said. "I can always go to the ATM and get more money."

By the time she closed up about 3 p.m., Kim had broken a record: 80 respondents.

Few said the $10 would survive their trip to Cowtown.

Even Ranginani found something: a crab cake sandwich and a Phillies hat to keep the sun out of her face.

"I'm a bit skeptical and my wife wanted nothing to do with it, but I asked the girls a million questions and they were up-front, so I gave them 10 minutes of my time," Steve Lineweaver, 54, of Salisbury Md., said while holding his bill. "That's a sausage sandwich right there."