The gender gap in certain scientific fields is narrowing.
But even as more women study biology and the physical sciences, the National Science Foundation says women earned only about one-quarter of undergraduate engineering and computer science degrees - down from their share two decades ago.
It's a concern for educators, who say more girls need to get interested in science for the United States to remain competitive in the global market.
The ELMO Lab is a sophisticated set-up at one of the nation's top universities, but it's designed for students who haven't even started school.
Hersek: Do you see the light anywhere?
Ader: Through your fingers. Oooh… I want to try…
Four-year-old Rachel Ader watches intently as scientist Marta Hersek explains how fiber optics work.
You're putting the light through, it's bending around, bouncing off through this tube and coming right out the other end.
The Northeastern professor is usually in front of a class of education majors, showing them how to engage young boys and girls in science.
You really do have to understand how kids learn and how they think, but also what they probably have already picked up from the world and elaborate on that.
You know they think science is cool because early on kids are excited about learning.
ELMO actually stands for Embedded Learning Modules but the name appeals to young kids.
Lab leader and physics professor Arun Benson says it's critical to introduce science early, especially to girls.
Kindergarten is not too early because what I find is as they progress through the grades, they somehow seem to lose interest in science even though there's a natural curiosity.
Studies show girls start to lose interest in middle school.
A summer program at Northeastern aims to counter that trend. It gives hands-on engineering and technology experience to more than 60 middle school kids who are minorities.
The majority are girls, like 11-year-old Celina Gonzales.
Rptr: Do you like science?
Gonzales: Not really.
Rptr: Why not?
Gonzales: It's kind of boring and it's just like hard.
This is a co-ed session but the girls and boys are in separate groups to make sure the girls aren't marginalized.
This week they're learning to write a computer program that will drive a Lego car.
Gonzales proudly lines hers up at the starting point.
It's actually going to go forward then it's going to try to get to that line and then it's going to turn and reverse to this tape.
It's those small successes where kids see how things worked and they got it to work to a certain point and then they realize, 'Now I have to do some alterations to do the next thing I want it to do.'
Randy August is an assistant professor of engineering in charge of the weeklong summer session.
Kids can continue their scientific explorations during the school year with after-school activities.
August says the program teaches information technology in a way that interests girls.
It's not the typical Newtonian physics-smash up-blow 'em up-type thing which the boys like but the girls shy away from.
So the central theme is assistive devices for the handicapped or the elderly.
Studies show that in general, girls like to build things that solve problems and help people.
Kendal Hoakstra, a math and technology middle school teacher in Boston, says she sees this in her class.
When we started this in my classroom - a very similar lesson with the Legos and engineering - they were hesitant because they've never had the experience with Legos.
Boys grow up with Legos and building things and girls don't, but I am amazed at how quickly they pick up on it and how they do enjoy it once they are exposed to it.
Researchers are now focusing on programs like Northeastern's that give girls science experience outside the classroom in the hope that will of encourage more girls to choose science as a career.
For Our World, I'm Monica Brady-Myerov in Boston.