When gravitational waves buzzed through the L-shaped LIGO detectors in Louisiana and Washington states last January, it marked the third such detection in as many years. Scientists and astronomy geeks went agog over yet another pair of black holes, whose merger rippled three billion light years across the universe.  

Shane Larson, Ph.D., a Northwestern University astrophysicist and member of the LIGO (Laser Interferometer Gravitation Wave Observatory) team, noted on the WriteScience blog that the three gravitational wave events are changing how we think about black holes. “LIGO is helping us do exactly what we wanted it to do: it is helping us learn,” he wrote.

Even as it detects three-billion-year-old events, super-sensitive LIGO also picks up random signals and noises called glitches that muddy up its gravitational wave data. So while LIGO is helping us learn about black holes, scientists need to help LIGO learn the difference between glitches and gravitational waves, a surprisingly difficult task. In a project called GravitySpy, everyday folks called “citizen scientists” examine and classify different kinds of glitches. This helps LIGO computers distinguish glitches from actual cosmic events. Dr. Larson says citizen scientists have already helped LIGO classify more than two million glitches.

No Ph.D. Required
“Citizen science is real science done by average citizens,” explains Chandra Clarke, author of “Be the Change: Saving the World with Citizen Science.” She adds, “It’s a little different than amateur science in that citizen science is usually organized by a professional scientist, and the work is done by groups of people. A citizen scientist can be anyone with an interest in doing science.”

Citizen science projects can involve counting birds, photographing leaves, identifying glitches, monitoring bees or flowers, measuring rainfall or river levels, tagging photos of animals or underwater landscapes or outer space, mapping squirrel populations, saving frogs and salamanders, protecting orchids, and hunting for exoplanets, to name just a few. Ms. Clarke says, it is more than amateur or hobbyist science; the data citizen scientists collect is incorporated into scientific databases, studies, reports, and even research papers, a number of which have credited citizen scientists as co-authors.

Also called crowd-sourced or participatory science, citizen science enables research on a human scale far beyond what most projects can provide or afford. Ms. Clarke, who has multiple science, English, and writing degrees, and runs CitizenScienceCenter.com, cites the Pavilion Lake Research Project as an example of how citizen science volunteers helped save thousands of costly research hours by examining underwater photos of two Canadian lakes.

“The researchers for this project had 1,113,706 images to look at,” Ms. Clarke explains. “Participants did this in a few weeks, submitted 1,481,526 classifications, and made 11,561 comments about what they saw under water. It would have taken a single scientist more than a year to do this, working flat out, 40 hours a week, and doing absolutely nothing else.”

A Worldwide Web of Armchair Scientists
Citizen science can bring together people age 5 to 95 from all over the world, says Laura Trouille, Ph.D., an astronomer and co-investigator with Zooniverse.org, which bills itself as an online platform for people-powered research. Zooniverse has attracted more than 1.5 million citizen scientists of all ages from 237 countries to participate in 68 projects run by hundreds of researchers. The primary motivator for most participants is a desire to contribute to science, Dr. Trouille explains, even if they have no scientific background.

“We have classrooms of kindergartners doing research, and an incredibly useful population of retirees doing projects as well,” says Dr. Trouille, who is also Director of Adler Planetarium’s Citizen Science program. “Across generations and across cultures, it’s a really interesting community of people with different interests and backgrounds.”

One of Dr. Trouille’s favorite Zooniverse projects is The Milky Way Project, in which participants identify elements such as “bubbles” and “bow shocks” in colorful infrared images of our galaxy, to help scientists understand more about star formation. Another is Snapshot Serengeti, where citizen scientists tag animals like wildebeest, vultures, lions, civets, even humans, in photos of Africa’s Serengeti National Park. Zooniverse offers a few history, literature and art projects, too, including AnnoTate, a collaboration with Britain’s Tate Museum to transcribe 20th century artists’ notebooks.

Citizen science “lifts the veil on how science works,” Dr. Trouille says, helping people understand the process of collecting, manipulating, and analyzing raw data, then coming to a research conclusion. Many projects host online forums where citizen scientists and researchers ask each other questions and share ideas about the project and the science involved. “A lot of discovery occurs in those discussion forums,” Dr. Trouille explains. “The volunteers feel comfortable offering new ideas and even making mistakes in front of the researchers. It’s a really important part of online citizen science in general.”

Centuries of Citizen Science
The Audubon Society’s Christmas Bird Count may be one of the most well-known citizen science projects, involving thousands of volunteers across Canada, the United States, Central and South America who count birds over a single 24-hour period. Started on Christmas day in 1900, the annual census helps ornithologists and biologists track bird health, behavior, and migration patterns, and guides conservation action.

Crowdsourcing scientific research goes back to at least 1776 in Virginia, when Thomas Jefferson organized the statewide logging of temperature and wind direction, said Caren Cooper, Ph.D., an ornithologist with North Carolina State University and author of “Citizen Science: How Ordinary People are Changing the Face of Discovery.” Back then, citizen scientists would have sent their data through the budding U.S. Mail service. By the mid-1800s, the Smithsonian Institution solicited volunteers to submit weather reports over the more timely telegraph system (at no charge). Today, more than 11,000 citizen science volunteers across the country record weather information for the National Weather Service’s century-old Cooperative Observer Network, which collects data via the (usually) lightning-fast Internet.

Indeed, the Internet has caused a “sudden explosion” of citizen science projects, says Ms. Clarke, enabling researchers to reach thousands of potential volunteers at little to no cost. The Internet also makes engaging in citizen science easy – from finding projects at numerous web sites (Google “citizen science projects”), to participating in computer- or smartphone-based projects, and submitting photos and data. The iTunes and Android app stores each offer at least 100 free citizen science apps for tablets and smartphones – just type “citizen science” into the search bar and browse the results.

Zooniverse’s Project Builder feature allows anyone to design and build their own citizen science project for free in just a few minutes – either a public project (which requires review and approval), or a private one to organize and promote as they wish. Dr. Trouille says teachers use Project Builder to manage class research projects, providing a space for students to upload photos, collect and analyze data, and discuss the results.

Can Regular Citizens Really Perform Good Science?

Some might question whether untrained people can reliably contribute to legitimate scientific research. Ms. Clarke admits there were early concerns about the validity of data collected or produced by non-professionals.

“But careful project design means that results are checked multiple times by multiple people in the project,” she says, “so the data is arguably more robust than it would be if only a few researchers were doing the work.”

Many Levels of Citizen Science
There are thousands of active citizen science projects out there, and different ways to participate. Ms. Clarke has identified six levels of involvement, from donating money to raising butterflies.  

Donate. When money is more abundant than time, help support research projects at crowdfunding sites such as Kickstarter, Indiegogo, Sciflies, and

Set and Forget. Citizen scientists can have their computers work on pieces of a research project during downtime. Check out the Berkeley Open Infrastructure for Network Computing (BOINC), whose projects include analyzing asteroids, testing climate change models, and decoding messages encrypted by Germany’s Enigma machines during World War II.

Web-based Citizen Science. Many citizen science projects require only a computer and internet connection, so participants can perform science sitting in a comfy chair at home. Projects include classifying drawings in Victorian-era science periodicals (Sciencegossip.org), transcribing 19th century ship’s logs (Oldweather.org), and identifying wildlife in photos of parks and other open spaces throughout Cook, Lake, DuPage, and Will counties (Chicagowildlifewatch.org).

App-based Citizen Science. Turn a smartphone or tablet into an on-the-go science tool with dozens of citizen science apps. Grow&Tell tracks what vegetable varieties grow best around the country with help from citizen science gardeners, while Loss of the Night monitors nighttime light pollution, or “skyglow,” around the world. Some apps are like games, such as The Great Brain Experiment created by neuroscientists at University College London. For more game-like apps, go to tinyurl.com/citizen-sci-games.

Get Outdoors. When it is time to take a computer break, go outside and perform citizen science. Although run locally through Chicago’s Peggy Notebaert Nature Museum, Project Squirrel wants citizen scientists all over North America to observe and record squirrel activity in their neighborhoods (Projectsquirrel.org). NestWatch encourages people to carefully visit bird nests and record information such as number of eggs laid, how many hatch, and how many hatchlings survive (Nestwatch.org). Through Monarch Watch, citizen scientists can plant their gardens with milkweeds, which monarch butterflies rely on for food, and order live caterpillars to raise into monarchs (Monarchwatch.org).

Other Ways to do Citizen Science. Ms. Clarke’s Level 6 or “other” citizen science category includes projects that record earthquake data (Quakecatcher.net ), monitor air quality (Aircasting.org), and get involved with do-it-yourself biology (DIYBio.org). Some of these projects require a testing kit or equipment that can be purchased directly or by donating to the project through a crowdfunding site.

To get started, pick an area of scientific interest – animals, plants, insects, microbes, sea life, astronomy, human behavior, etc. – and search for related projects at one of the many citizen science sources. Citizen scientists can usually get started on a project right away.

“Instead of filling your commute time with Candy Crush, go download the Zooniverse app and pick a project on that app that appeals,” advises Ms. Clarke. “They all come with tutorials and easy tasks to complete. You’ll be glad you did.”