President's Professor searches for life on virtual worlds

With billions of galaxies in the known universe, each containing billions of stars, what do you think the odds are that other life forms exist somewhere out there? Probably pretty good. But where do you begin this cosmic search? It could be a class called Habitable Worlds, which is offered fully online at Arizona State University, and which has already been taken by more than 1,000 students.

Habitable Worlds is not just a class that addresses the age-old question: “Is there anyone out there?” It also teaches students how to think like scientists and uses the power of the Internet and the intuition of a tech savvy generation to kindle their interest and spur their education.

“Most science classes teach science as facts and answers,” says Ariel Anbar, a professor in the School of Earth and Space Exploration (SESE) and the Department of Chemistry and Biochemistry, and one of the driving forces behind Habitable Worlds. “We are trying to show students that science is really a process – a process that first helps us organize our ignorance about questions to which we don’t have answers, and then helps us narrow the uncertainties so that we gradually replace ignorance with understanding.”

Anbar, recently named a President’s Professor, believes this course is a natural online offering, so long as it uses the delivery medium to its advantage. That means engaging the students and enticing them through interactive exercises.  

Anbar has been a leader in online learning at ASU and nationally, and is deeply involved in using the medium to its fullest to help educate and encourage a generation that has grown up with the Internet. Part of his becoming a President’s Professor is in recognition of his pioneering online teaching efforts.

Habitable Worlds – developed through ASU Online – is organized around a game-like activity using a goal-oriented format, integrating several traditional areas of science that are usually taught separately - like astronomy, planetary sciences and geology.

“We want students to go through the same processes we go through as scientists,” says Anbar of the course. “The best way to learn science is to do science.”

Anbar and Lev Horodyskyj, a course coordinator in SESE and co-developer of the course, have made HabWorlds into a bit of a treasure hunt, writ large.

At the beginning of the term, they assign a star field to each student and in that field they search for a habitable world. To carry out the search in this “habitable hunt,” students need to know what they are looking for. They need to understand the various classes of stars, some of the observed traits of each, to figure out which ones could nurture life, and how physics, chemistry and geology come together to determine whether a planet can harbor life. The quest motivates them to learn these concepts.

For example, in a lesson on the stability of liquid water, a key ingredient for any alien “Earth-like” planet, students use a simulator to explore the stable phase of water under pressure and temperature conditions found on Mercury, Venus, Earth, the Moon and Mars. The data students collect are plotted in real time, giving them enough information to plot boundaries between the three phases of water, if they conduct a comprehensive experiment (they are gently prodded through the experiment if it falls short). Essentially, students build a phase diagram of water (a basic concept taught in introductory chemistry) from observed data, rather than having it handed to them and told, “That's the way it is,” Horodyskyj says.

Once students discover a scientific concept through this kind of basic experimentation, the lecture component kicks in, reviewing what they discovered and why these relationships exist. The lesson is reinforced through an application activity where students use the concepts they have discovered to make predictions about environments and conditions they have not previously explored. These concepts are directly applicable to the habitable hunt, where students are expected to identify that this concept is important to completing their mission and apply it without being instructed on when or where to use it.

“We strive to show students that science is an iterative process, where we use data to build models, then use those models to make predictions about what data we will find next, and use that new data to further refine our models,” Horodyskyj says. “This is the essence of understanding our universe and there's no better way to teach it than to have students engage in that process throughout the term.”

“They basically are going through the same steps that you would want students to go through in an in-person laboratory class,” Anbar says of the online activities. “They observe, develop a hypothesis, test the hypothesis and log data. Along the way, students learn some of today’s basic science concepts and techniques, like spectroscopy, the Planck function, thermal emission and how stars work. It is serious, college-level science. But they don't just listen to a lecture. They engage, hypothesize, test and evaluate. We want them to gain a deeper understanding of how science works, teaching them to think critically along the way.”

The course makes use of immersive, media-rich simulations that let students explore perspectives and locations that would otherwise be inaccessible. For example, one simulation lets students create stars of different masses so that they can discover the properties of different types of stars. Another, a “virtual field trip,” takes them to South Australia where they can explore in detail, fossils of the earliest animals on Earth. The virtual field trips were produced as part of a project with the NASA Astrobiology Institute (NAI). Anbar directs the NAI team at ASU.

“The simulations take advantage of the digital medium to deliver experiences that can't be done nearly as well in a lecture hall,” explains Anbar.

The simulations, lectures and assignments are pulled together using an internet-based learning platform developed by an Australian startup company, Smart Sparrow.

“The learning platform is the secret sauce,” says Anbar. “It isn't as flashy as the simulations, but it’s what lets us build rich, game-like lessons that make use of those simulations and adapt to what the students do. It’s a bit like the way that PowerPoint enables us to make beautiful and informative slide shows. Without that software, all we’d have are a bunch of links to cool simulations. With the software, we can build an interactive and adaptive learning experience.”

It's not all fun and games, though. Because it is a course that counts for quantitative science credit, students are required to do a fair amount of math.

“What we try to do is get the students to see that the equations they are working with actually describe what they see in many of the simulations,” Anbar says. “The equations describe phenomena that are interesting and powerful in answering questions that the students need to answer. They use the math in the equations to solve challenges they encounter in the habitable hunt.”

“The goal is to get them to see the way scientists see the value of quantitative thinking, the value of math,” he adds. “We want to show that math can be used for something other than to solve a problem in a homework assignment. Math can be used to help answer a question they care about, like are we alone?”

Anbar and professor Steve Semken of the School of Earth and Space Exploration recently received funding from the National Science Foundation to run an assessment of HabWorlds to see if the class is successful. Over the next three years, Anbar, Semken and Horodyskyj will be testing students who have completed the course to see if they exhibit scientific reasoning skills. They also will test the technology used in the online course and compare that experience with in-person learning.

With the class being virtual, Anbar has taken time to step back and see if he is being as effective as he can be in teaching HabWorlds. While it still may be early, he has gotten a fair amount of positive feedback from students. Contrary to what many expect, Anbar finds that teaching a class of 400 online students can be more personal than teaching 400 students in a lecture hall. Part of that advantage is student acceptance of the teaching medium.

For example, students are less intimidated by the instructor and more freely communicate online. While uninhibited Internet posts can cause problems, Anbar says that they ultimately give him more insight into how and why students are struggling, and give rise to opportunities to make personal connections with individual students.

“I’ve had more interaction with students in my large online classes than in large face-to-face classes. Working online lets you get to know some of the students in the context of their lives,” Anbar says. “With the limited contact time of lectures, all I may really know is I have this student who is struggling. Half the time those students don’t even show up.”

“With online courses, and with students who are comfortable interacting online, they tend to let you know what they think,” Anbar says.  “Sometimes they express it inappropriately, but when my TAs and I show them that we’re listening, and that we care, we are able to reach students who otherwise would just be I.D. numbers on a spreadsheet. Some of these interactions have been really powerful and moving.”

Another benefit is that motivated students step up to help others.

“In any large class, there are usually a few students who easily grasp the material and are willing to help others,” explains Anbar. “Usually, they can only help a few of their friends. But in an online class they are like bonus teaching assistants. They are sometimes even better than the teaching assistants because they can easily put themselves in the shoes of their peers and offer really effective advice.”

Anbar says there is great potential with the online medium in higher education that he’s only begun to tap. Online classes could be designed with intelligent, adaptive tutoring to guide students through difficult content, he explains. They could incorporate deeper social networking to encourage rich, spontaneous interactions with peers and teaching staff, potentially turning large scale from a liability to an advantage.

When thinking about the tools at his disposal and the number of students enrolling in HabWorlds, Anbar is excited about his future as a teacher.

“I’m doing online what I could never do face-to-face,” he says.