| Lola Figueroa Clark doesn't have her advanced degree in marketing yet.

But at 8 years old, the Mount Airy third grader already knows why construction toy manufacturers like K'nex Brands L.L.C. in Hatfield become so frustrated when marketing to girls.

"Boys and girls both like" construction toys, Lola said. "But if you want to look for them in the toy stores, you have to look in the boys' section."

The result? In the growing $1.8 billion building and construction toy market, nearly half the potential buyers (i.e., girls) are not coming into regular contact with their product.

This weekend, K'nex hopes to change that at the New York Toy Fair, attended by more than 30,000 toy retailers, manufacturers, journalists, and toy industry insiders.

K'nex plans to use the Toy Fair, which ends Tuesday, to launch Mighty Makers, a line of construction toys aimed at girls.

The Mighty Makers sets of rods and spokes eschew K'nex's usual bright primary colors, part of the construction elements of K'nex vehicles, dinosaurs, robo-creatures, trucks, planes, Ferris wheels, and roller coasters.

Instead, rods and spokes in tones of magenta, apple green, and gold can be turned into Ferris wheels and airplanes, but also butterflies, windmills, a deep-sea diving boat, or three varieties of houses.

In the toy world, designing specifically for girls is fraught with gender politics - politics that came under debate within the all-female design and marketing team assigned to the project at the K'nex design studios in Hatfield.

"The biggest challenge is industry insiders," said Kristen Krikorian, director of marketing at K'nex. "There's been a bias that building toys are only for boys."

One problem

The market seems to bear that out. According to the NPD Group, a market research company, only 20 percent of sales of building toys can be attributed to girls.

In theory, the argument goes, girls and boys should not be forced into gender stereotypes and should be free to play with whatever toys they like, from doll babies to trucks.

If that's so, then why should there be a separate line of products?

These questions even came up in-house at K'nex, said Heather Croston, design manager for Mighty Makers.

"There was a little bit of questioning whether we needed to do something for girls when we make a gender-neutral toy."

Except for one problem - and the problem is pink.

When Krikorian, Croston, and assistant brand manager Erica Schnebel watched a focus group of girls play with their products, the girls went right to a box of pink K'nex toys, bypassing K'nex's primary colors.

Even so, a common way to botch cross-gender marketing is to dye toys pink, said Chris Byrne, a longtime toy critic and now content director of TTPM, Time to Play Magazine, an online trade publication.

"The trick has been to do more than switch to pink," said Byrne, who will be in New York for Toy Fair.

What's key, said Byrne, is to understand that even though girls and boys like construction toys, they play with them differently.

In January 2012, after extensive study, the Lego Group used insights gained in its research to launch its girls' line, Lego Friends. The success of Lego Friends encouraged other toy manufacturers, like K'nex, to follow suit, Krikorian explained.

Girls, it turned out, like to build together. Even if girls are working individually, they will advise and comment on each other's projects. Boys prefer to work alone.

Girls also tend to pay more attention to detail and to follow instructions.

Most important, girls want to incorporate a story into their play experience. So, in a building kit, they want more figures.

In the Mighty Makers kits, the figures are not generic drivers or pilots. Ava, an aviator, pals around with a bird, Jay, and Marissa explores the sea with her fish, Queen.

"Girls want to interact with their projects," Schnebel said.

The female K'nex design and branding team insisted that the girls' play sets not be stereotypical.

"Why does the girl have to build a cupcake shop?" Croston said. "Why can't she be an explorer?"

Kid stuff

She and her team were eager to build play sets that encouraged girls to be mighty in STEM disciplines: science, technology, engineering, and math.

"There's all this emphasis on STEM now, but at the end of the day, most toys are being purchased at the request of a child," Byrne, the toy critic, said.

"A lot of the STEM stuff is the parents' idea," he said. "You are marketing to parents. STEM is a nice adult-centered marketing hook. Parents may buy it, but it doesn't mean their kids are going to buy it."