Australian Researcher Uses RFID to Track Preschoolers’ Activity Levels

By Claire Swedberg

The project's goal is to learn how teachers can influence their students' behavior, with the premise being that greater physical activity improves a child's health and well-being.


Karen Tonge, a researcher with the University of Wollongong’s Early Start Research Institute (ESRI), is using an RFID-based solution to track the movements and proximity of students and educators in preschool playgrounds, thereby providing insight regarding how much teacher engagement influences the level of activity in children. The study will aim to provide educators and other interested parties with information regarding the extent to which teachers can influence how active children are during their early education years. The premise is that the more physically active a child is, the better that individual’s health and well-being will become.

To track the locations and movements of students and teachers, Tonge is employing battery-powered RFID tags and fixed readers provided by Convergence Systems Ltd. (CSL). The students and teachers also wear ActiGraph battery-powered devices that contain accelerometers for measuring the quantity and intensity of a person’s movements. The collected movement data is then manually compared against the RFID-based location data to determine where an individual was, and with whom. However, Tonge says, she is currently working with other researchers to develop a software program that would integrate the ActiGraph accelerometer data with the RFID real-time location system (RTLS) data, in order to create an automatic link between location and movement intensity.

At each participating school, Tonge installs several CSL RTLS RFID anchor readers, each plugged into a power source.

Tonge is working with the Early Start Research Institute to earn her doctorate in education. She began the three-year study in early 2014 after discussing her research project with Tony Okley, ESRI’s research head, who was familiar with CSL’s RFID technology. Simply observing children’s activity would not provide the detail of activity data that the study would require, she explains, so she launched the project using the RFID wristbands and readers.

By the time the project is finished, it will have involved up to 600 preschoolers (ages two to five) at 15 preschools located in New South Wales, as well as up to 100 educators who work with those children. To date, Tonge has installed the technology at six preschools in the Wollongong area, for about one week at each site.

Tonge opted to conduct the study only during outdoor playtime, when children are expected to be most active.

Each participant, whether adult or child, wears an ActiGraph wGT3X-BT device attached to his or her waist to track movement intensity, as well as a CS3151BBCD RFID tag, which looks a wristwatch. Tonge installs CSL RTLS RFID anchor readers, each plugged into a power source. The anchor readers transmit location data to a CSL RTLS RFID gateway reader connected to a laptop running CSL software, which computes each person’s location.

Tonge arranges the readers in such a way that they provide data that the software can use to triangulate the tags as they move through a playground. That means she must, at times, be creative in how those devices are installed. “They can be in a shopping bag,” Tonge states, “hanging from a tree,” for instance, or mounted on a fence, wall or shelf. She installs at least four readers but sometimes as many as eight, depending on a playground’s size and shape. “Some [playgrounds] are a lovely rectangle, but others have an L shape or a more awkward shape, in which case I have used up to eight readers.”

One of the project’s preschoolers, wearing a CSL RFID tag on her wrist and an ActiGraph battery-powered activity monitor on her waist.

Once Tonge installs the readers, she registers each device’s GPS coordinates into the CSL software, which is then used to display a map of the playground. The interrogators themselves create a wireless mesh network to funnel their data to the gateway reader. The CSL software running on the laptop uses triangulation to track each tag’s movements. Tonge then inputs data that can be overlaid on the map, such as the location of a sandpit, a picnic table or playground equipment. “I want to be able to see the different features in each environment,” she explains, in order to determine how those features might influence activity as well.

Each RFID tag uses a proprietary air-interface protocol to transmit a 2.4 GHz signal encoded with a unique ID number. That ID is associated with a student or teacher wearing that tag, although the individual’s identity is not tracked. When adults or children wearing the tags are in the playground in which the readers are deployed, the CSL software identifies each wristband’s location in real time and displays an icon (E for educator or C for child) as the person wearing it moves around the playground.

As the teachers and students travel throughout the playground, the CSL software not only captures the movement data in real time, but also stores that information for the purpose of analytics. Tonge says she can view such details as how often educators come in close contact with children, how active kids are in the presence of teachers, and when specific students (based on an anonymous ID number) may be receiving more or less time with educators during playtime.

“I can also watch movements as they are actually happening,” Tonge adds, recalling one day in which a garbage truck came within viewing range of a preschool playground. As the truck arrived, she says, “I could watch all the little dots go to the fence, and then follow along the fence” as the vehicle passed.

The study, which is slated to conclude in 2017, has already generated considerable data, Tonge says, though she has yet to perform much analysis of the results. “The information we are getting from the services [preschools] is so diverse,” she states. For example, some schools have more educators per the number of children, some vary routines and programs, and some have a higher level of activity among both children and educators.

Karen Tonge

Wearing the RFID wristbands was an easy sell for students, Tonge says. “The children love them. I’m known as the watch lady,” she states, adding that the kids are eager to put the devices on their wrists. The tags must be durable, she notes, since they are being issued to small children. For instance, they have been buried in sand, as well as covered with paint and modeling clay. But according to Tonge, they still operate well under such conditions.

The technology itself has a lot of potential for schools, Tonge says, since it enables a preciseness of tracking student and teacher behavior that isn’t possible manually.

Describing her goals for the research project, Tonge says, “I hope to contribute to my field by informing educators of their role in engagement with children and the resulting activity levels, in hopes of influencing policy and practice.”

Tonge adds, “By 2017, I will have a very clear picture of how an educator can influence activity levels in children.” She plans to make the results of her work available to researchers, teachers and others in the education sector, for use in organizing preschool programs, preschool-age activities, environments, teacher training and student-per-teacher structures.