Jul 20, 2017 11:16 PM
(This post was last modified: Jul 20, 2017 11:42 PM by C C.)
Teaching without training
https://www.eurekalert.org/pub_releases/...071917.php
RELEASE: Ryan Nixon spent four years studying matter, energy and the universe -- and learning how to teach those and other physics-related concepts to teens. In his first year as an eighth-grade teacher, he hit a roadblock. He was supposed to teach his students geology: something he hadn't learned a thing about since, well, eighth grade.
"As a new teacher, you don't know what you're doing, but if you let teenagers know, that's not a good thing," he said.
Nixon, now a Brigham Young University assistant professor of science education, teamed with colleagues from the University of Georgia to explore both the rates and predictors of secondary science teachers who were assigned classes out of field, focusing on teachers in their first five years on the job. Among their findings: 40 percent of these new teachers taught mostly or entirely out of field, and 64 percent had at least one out of field course in their first five years.
The team focused on early career teachers, he said, because it's a group already facing myriad challenges adapting to the classroom setting: 50 percent don't make it past their fifth year. "When you're a new teacher and you want a job, you take the job the principal gives you," he said. "And if you're assigned out of field, maybe you figure it out and do a good job with it, but it makes your life hard."
Though past research has looked at various aspects of out of field teaching, this is the first study that has explored secondary science out of field teaching in the No Child Left Behind (NCLB) era. In 2004 NCLB mandated that teachers be "highly qualified" in their subjects, which at first, Nixon said, essentially prohibited out of field teaching. But with a loosened definition of "highly qualified," just 36 percent of new science teachers are teaching only in their trained subject.
Those numbers, Nixon said, aren't great news for students either. "Their teachers are working really hard, but they're teaching subjects they're not really prepared to teach. And the teacher can try again next year, but if you're the kid in 11th-grade chem, you don't get to try again."
But science is science is science, right? Nope.
Each of the disciplines has its own areas of focus, structures, rules, methodologies, languages. When teachers don't know the content of a particular discipline, Nixon said, their classes become more constrained, more about rote memorization and repetition than working through ideas in depth.
"If science teaching and learning is about making sense of the world and understanding how experts in these disciplines work, then that's an issue," he said.
One particularly troubling finding in the study was that urban and rural schools and schools with high English-language-learner populations are more likely to have teachers doing out of field instruction. These schools, Nixon noted, are often already underfunded and often already have more new teachers than other schools. "It's just adding to the challenges these students are already facing to be given these teachers who aren't prepared to teach the things they're teaching."
Though the problem has its root in a number of areas, including vague policy, Nixon believes important change can come when administrators are aware of the issue.
"I wonder if administrators really realize it's a problem. 'You're a science teacher: why does it matter? Teach whatever,'" he said. "But when it comes down to it, administrators need to say, my teachers need to be where they can teach best."
Robotics-based study provides insight into predator-prey interactions
https://www.eurekalert.org/pub_releases/...071917.php
RELEASE: Researchers have recently gained advanced understanding of a variety of processes through the information-theoretic concept of transfer entropy. Today, scientists are able to explain coupled dynamical systems like functional connective patterns in the brain and climate patterns all around the globe. Researchers from New York University's department of mechanical and aerospace engineering in Brooklyn found this method to hold great promise for advancing our understanding of animal behavior, particularly related to predator-prey interactions.
A research team led by New York University professor Maurizio Porfiri put forth a robotics-based study to control information flow in predator-prey interactions, as well as test the validity of transfer entropy when attempting to understand causal influences of the system. They report their findings this week in the journal Chaos, from AIP Publishing.
Specifically, the team studied the behavioral response of a zebrafish subjected to a fear-evoking robotic stimulus, modeled after the morpho-physiology of a red tiger oscar fish. They programmed the robotic threats to actuate along specific trajectories establishing a controlled, one-directional information flow. The predator motion in this interaction was independent of the response of the prey.
"Something which is really important from our community point of view is to be able to merge robotics and dynamical systems to address questions in animal behavior," Porfiri said.
As expected by the researchers, transfer entropy was able to isolate the causal relationship underlying experimental observations, and they were able to show a one-directional informational flow from the stimulus to the zebrafish.
Expanding on their validation of transfer entropy in the controlled robotics-based setup, the research team studied interactions between a zebrafish and a live red tiger oscar fish (whose response to the zebrafish could not be controlled). Unlike the robotics-based interaction, transfer entropy did not overly identify a direction of information flow in the presence of a live predator. So not only was the zebrafish influenced by the predator, but also the predator reacted to the zebrafish, in a two-directional interaction.
"We are able, from raw data, to understand that both the predator and the prey modify their behavior once one is in the presence of each other," Porfiri said.
To provide some biological basis for the observed difference in information flow, Porfiri and his group studied the specific reactions of the predator in response to the presence of the prey. Although their experimental setup could not fully replicate the habitat of the red tiger oscar fish, they observed basic behavioral reactions observed in the wild, verifying the fish's natural hunting instincts still played a role in their reactions.
Although there is still more to understand regarding the behavior of prey and predators, the researchers demonstrated the validity of transfer entropy to discover a cause-and-effect process, which has important implications in science and engineering. This is especially interesting from the perspective of the many potential ways robotics can help us understand how species share and use information.
###
The article, "Information theory and robotics meet to study predator-prey interactions," is authored by Daniele Neri, Tommaso Ruberto, Gabrielle Cord-Cruz and Maurizio Porfiri. The article appeared in Chaos July 18, 2017 [DOI: 10.1063/1.4990051] and can be accessed at http://aip.scitation.org/doi/full/10.1063/1.4990051.
ABOUT THE JOURNAL
Chaos is devoted to increasing the understanding of nonlinear phenomena in all disciplines and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See http://chaos.aip.org.
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https://www.eurekalert.org/pub_releases/...071917.php
RELEASE: Ryan Nixon spent four years studying matter, energy and the universe -- and learning how to teach those and other physics-related concepts to teens. In his first year as an eighth-grade teacher, he hit a roadblock. He was supposed to teach his students geology: something he hadn't learned a thing about since, well, eighth grade.
"As a new teacher, you don't know what you're doing, but if you let teenagers know, that's not a good thing," he said.
Nixon, now a Brigham Young University assistant professor of science education, teamed with colleagues from the University of Georgia to explore both the rates and predictors of secondary science teachers who were assigned classes out of field, focusing on teachers in their first five years on the job. Among their findings: 40 percent of these new teachers taught mostly or entirely out of field, and 64 percent had at least one out of field course in their first five years.
The team focused on early career teachers, he said, because it's a group already facing myriad challenges adapting to the classroom setting: 50 percent don't make it past their fifth year. "When you're a new teacher and you want a job, you take the job the principal gives you," he said. "And if you're assigned out of field, maybe you figure it out and do a good job with it, but it makes your life hard."
Though past research has looked at various aspects of out of field teaching, this is the first study that has explored secondary science out of field teaching in the No Child Left Behind (NCLB) era. In 2004 NCLB mandated that teachers be "highly qualified" in their subjects, which at first, Nixon said, essentially prohibited out of field teaching. But with a loosened definition of "highly qualified," just 36 percent of new science teachers are teaching only in their trained subject.
Those numbers, Nixon said, aren't great news for students either. "Their teachers are working really hard, but they're teaching subjects they're not really prepared to teach. And the teacher can try again next year, but if you're the kid in 11th-grade chem, you don't get to try again."
But science is science is science, right? Nope.
Each of the disciplines has its own areas of focus, structures, rules, methodologies, languages. When teachers don't know the content of a particular discipline, Nixon said, their classes become more constrained, more about rote memorization and repetition than working through ideas in depth.
"If science teaching and learning is about making sense of the world and understanding how experts in these disciplines work, then that's an issue," he said.
One particularly troubling finding in the study was that urban and rural schools and schools with high English-language-learner populations are more likely to have teachers doing out of field instruction. These schools, Nixon noted, are often already underfunded and often already have more new teachers than other schools. "It's just adding to the challenges these students are already facing to be given these teachers who aren't prepared to teach the things they're teaching."
Though the problem has its root in a number of areas, including vague policy, Nixon believes important change can come when administrators are aware of the issue.
"I wonder if administrators really realize it's a problem. 'You're a science teacher: why does it matter? Teach whatever,'" he said. "But when it comes down to it, administrators need to say, my teachers need to be where they can teach best."
Robotics-based study provides insight into predator-prey interactions
https://www.eurekalert.org/pub_releases/...071917.php
RELEASE: Researchers have recently gained advanced understanding of a variety of processes through the information-theoretic concept of transfer entropy. Today, scientists are able to explain coupled dynamical systems like functional connective patterns in the brain and climate patterns all around the globe. Researchers from New York University's department of mechanical and aerospace engineering in Brooklyn found this method to hold great promise for advancing our understanding of animal behavior, particularly related to predator-prey interactions.
A research team led by New York University professor Maurizio Porfiri put forth a robotics-based study to control information flow in predator-prey interactions, as well as test the validity of transfer entropy when attempting to understand causal influences of the system. They report their findings this week in the journal Chaos, from AIP Publishing.
Specifically, the team studied the behavioral response of a zebrafish subjected to a fear-evoking robotic stimulus, modeled after the morpho-physiology of a red tiger oscar fish. They programmed the robotic threats to actuate along specific trajectories establishing a controlled, one-directional information flow. The predator motion in this interaction was independent of the response of the prey.
"Something which is really important from our community point of view is to be able to merge robotics and dynamical systems to address questions in animal behavior," Porfiri said.
As expected by the researchers, transfer entropy was able to isolate the causal relationship underlying experimental observations, and they were able to show a one-directional informational flow from the stimulus to the zebrafish.
Expanding on their validation of transfer entropy in the controlled robotics-based setup, the research team studied interactions between a zebrafish and a live red tiger oscar fish (whose response to the zebrafish could not be controlled). Unlike the robotics-based interaction, transfer entropy did not overly identify a direction of information flow in the presence of a live predator. So not only was the zebrafish influenced by the predator, but also the predator reacted to the zebrafish, in a two-directional interaction.
"We are able, from raw data, to understand that both the predator and the prey modify their behavior once one is in the presence of each other," Porfiri said.
To provide some biological basis for the observed difference in information flow, Porfiri and his group studied the specific reactions of the predator in response to the presence of the prey. Although their experimental setup could not fully replicate the habitat of the red tiger oscar fish, they observed basic behavioral reactions observed in the wild, verifying the fish's natural hunting instincts still played a role in their reactions.
Although there is still more to understand regarding the behavior of prey and predators, the researchers demonstrated the validity of transfer entropy to discover a cause-and-effect process, which has important implications in science and engineering. This is especially interesting from the perspective of the many potential ways robotics can help us understand how species share and use information.
###
The article, "Information theory and robotics meet to study predator-prey interactions," is authored by Daniele Neri, Tommaso Ruberto, Gabrielle Cord-Cruz and Maurizio Porfiri. The article appeared in Chaos July 18, 2017 [DOI: 10.1063/1.4990051] and can be accessed at http://aip.scitation.org/doi/full/10.1063/1.4990051.
ABOUT THE JOURNAL
Chaos is devoted to increasing the understanding of nonlinear phenomena in all disciplines and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See http://chaos.aip.org.
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