Course Review: Astronomy: Exploring Time and Space

As I mentioned a few weeks ago, I recently took the Coursera class Astronomy: Exploring Time and Space, from the University of Arizona‘s Dr. Chris Impey. This review is written based on the course as it existed in March 2015.

This review serves three functions:

  • For prospective students, should I take this course?
  • For prospective employers and admissions offices, what does having completed this course say about a potential employee or student?
  • For course developers and educators, what can I learn from how this course is developed and delivered?

This review will contain two parts: an objective description of the course content, structure, and experience, and a subjective analysis of the course’s value to students, employers, and educators.

Course Description

Astronomy: Exploring Time and Space is a six-week class covering the basics of Astronomy, including the tools of astronomy,  the planets and the solar system, extraterrestrial life, and the origins of the universe. The full description is available here. The course is self-described with the following:

This course is designed for anyone who is interested in learning more about modern astronomy. We will help you get up to date on the most recent astronomical discoveries while also providing support at an introductory level for those who have no background in science.


Astronomy: Exploring Time and Space was a six-week course. Each week consists of a couple hours of pre-prepared video material, a couple quizzes over the material, and either a peer-reviewed writing assignment or an interactive activity.

Overall, the course can be completed in around thirty total hours including all activities. The lecture material averages two to three hours per week, while the quizzes, assignments, activities, and peer review total likely another hour.


Astronomy: Exploring Time and Space is broken into six units: “Our Place in the Universe”, “The Tools of Astronomy”, “Planets Near and Far”, “Star Birth and Death”, “Galaxies and the Big Bang”, “Life in the Universe”. Each unit is built around its overarching topic, and examines multiple elements of the topic. For example, the third unit — “Planets Near and Far” — covers the nearby planets, then the methods for examining planets further away, then interesting features of further-out planets.

Astronomy: Exploring Time and Space assumes nothing about the student’s knowledge; it is accessible to anyone. It goes so far as to start with the very basics of the scientific method: how science works, how observation, discovery, and reasoning lead to the scientific method, and how the scientific method is used in the context of astronomy. In line with this, Astronomy: Exploring Time and Space also keeps things high-level and accessible; little math is covered, and while the concepts covered are complex, the course focuses on giving beginner-level explanations. Rather than complex equations and slides of bullet points, Astronomy: Exploring Time and Space makes heavy use of animations, visualizations, and simulations. The course also injects a significant dose of humor and popular culture.


There are three types of assessments in Astronomy: Exploring Time and Space:

  • Thirteen short lecture quizzes (six questions each), made exclusively of multiple choice questions and permitting three retakes.
  • Three short writing assignments (500 words each) that are graded via peer grading.
  • Two activities using external sites, graded via some multiple choice questions.

Assignments are assigned to three peer graders for peer review, and each student grades three classmates’ assignments.


There are no necessary prerequisites for this class. I wouldn’t have any hesitation giving it to middle school students, and yet the course material should remain interesting to students with higher-level degrees but no experience in astronomy.

Identity Verification

For Verified Certificates ($50 at the time that I signed up), students complete the Coursera two-phase authentication: a typing sample is submitted and a picture is taken of the student immediately after completing the assessment. Assuming that these are adequate in ascertaining the student’s identity, they are nonetheless not difficult to circumvent. It would be trivial to collaborate with someone else on the assignments or even outright submit someone else’s work. This verification only assures that the student was present when the work was submitted.

If the student is not enrolled in a Verified Certificate, there is no identity verification at all.

Course Analysis

Astronomy: Exploring Time and Space uses a “talking head” approach throughout much of its presentation, but that approach is very often augmented with visuals, diagrams, animations, simulations, videos, and other forms of media. Additionally, despite the talking head approach, there are never any visuals resembling PowerPoint slides — the class is much more conversational. The ultimate effect of this is that the lectures are actually downright pleasant to watch. It feels like attending an interesting guest lecture or watching a well-prepared (albeit low-budget) documentary.

The assessments of Astronomy: Exploring Time and Space generally suffer from the structure I’ve seen commonly used in Coursera courses. The quizzes allow two immediate retakes, meaning that guess-and-check can earn a surprisingly good score on the quizzes. The writing assignments and the activities, however, do encourage significantly deeper understanding of the material for those topics covered by those activities — but as with most things, you get out of these what you put into them.

Aside from the lessons and the assessments, the course consists of the typical forums as well as a number of live sessions with Dr. Chris Impey. The forums, like many Coursera courses, are somewhat hit or miss: in this class a community didn’t seem to develop and most discussions did not go anywhere. The live sessions, however, were very interesting. Dr. Impey’s impromptu ability to answer some deep questions was particularly amazing. It would have been great to see an actual synchronous conversation on some of the questions that were brought up.

For Prospective Students

Astronomy: Exploring Time and Space is an excellent introduction to the high-level concepts of astronomy. It’s accessible to beginners in the field, so no prior knowledge is required. It nonetheless also goes deep enough into the topic to be fulfilling. I left the course wanting to know more, but I didn’t feel like the course itself should have gone in more depth on any particular topic. The title of the course is appropriate: it’s an exploration of time and space. It doesn’t cover every single thing, nor should it.

Take this course if:

  • You enjoyed Cosmos: A Spacetime Odyssey and want to learn more.
  • You have any interest in astronomy, but little prior experience.
  • You’re willing to do a little more than the traditional Coursera multiple choice quizzes (but not too much).
  • You have trouble learning from the traditional talking-head-and-slides presentation style.

Don’t take this course if:

  • You already have an intermediate background in astronomy (you likely know the course content already).
  • You’re looking for a class to replace a high school or college-level astronomy credit (the material and assessments aren’t quite deep enough to replace these classes).
  • You don’t want to write a couple essays.

For Prospective Employers and Admissions Offices

With regard to identity verification, the identity verification for the Verified Certificate is trivial to circumvent. Thus, a Verified Certificate in Astronomy: Exploring Time and Space should carry limited clout for that reason alone. The remaining analysis will infer that the student did complete the certificate themselves.

With regard to assessment, the rigor of the course is slightly higher than many other MOOCs, but not high. As referenced above, the multiple choice quizzes are easy to game without actually learning the material, meaning that the only reliable assessment is the written assignments. These are most certainly a matter of getting out of them what you put into them. In peer grading, I saw a wide variety of assignments, from comprehensive essays to three-sentence throwaway answers. While I, personally, have some reservations about the validity and reliability of peer grading, research has shown this approach to be effective.

With regard to content, Astronomy: Exploring Time and Space provides a strong overview of the basic principles of astronomy. Neither its coverage nor its assessments are sufficient to consider it as a potential replacement for high school or college credit, but it’s sufficient to demonstrate interest and qualification for taking a class that might otherwise appear to be out of the student’s ability level.

Personally, if I saw Astronomy: Exploring Time and Space on an applicant’s resume for admission to school or for a job, I would take it as a sign that the applicant has their own interests and is willing to put up more than minimal effort to pursue those interests. I wouldn’t derive any more conclusions based on this certificate, but that alone may be interesting to note.

For Course Developers and Educators

There are three main things in Astronomy: Exploring Time and Space that I’d like to see more courses do:

  • Diversify video content. Many courses are almost entirely comprised of a talking head alongside a set of PowerPoint slides. I understand the temptation of doing that; it’s easy, and Coursera courses aren’t money-makers, so the costs of production need to be kept low. However, I would not speculate that Astronomy: Exploring Time and Space cost more to produce than others; the time spent developing slides was simply instead spent gathering visuals and other resources. That’s a better use of the time in any course that can present content using something besides bulleted lists of vocabulary words and concepts. Astronomy: Exploring Time and Space is the first MOOC I’ve taken that I can imagine airing on television for a casual audience.
  • Diversify assessments. Many courses rely only on auto-graded multiple choice quizzes with several retakes. I find very little reliability in a person’s record from a course entirely made up of these assessments; anyone can complete them. The peer-graded assessments in Astronomy: Exploring Time and Space as well as the lecture activities (even though they are evaluated by similar quizzes) at least require student participation that cannot be totally faked. Better plagiarism detection measures could make this even more powerful.
  • Know your audience. The best part of Astronomy: Exploring Time and Space, to me, was in its cohesiveness and consistency. The entire course stays at the same level of presentation complexity and content depth. It knows its audience is novices to astronomy, and so it focuses on keeping things accessible, interesting, and enjoyable to watch. Not every class should focus on a beginner audience this way, but every class should know who its audience is and consistently cater specifically to that audience.

For more information, please see the course web site. If I’ve left out anything crucial to understanding this course, let me know below!

Share on Google+Share on FacebookTweet about this on TwitterShare on LinkedInShare on RedditPin on PinterestEmail this to someone

Astronomy: Exploring Space and Time: First Week Impressions

As I mentioned Monday, I started my first Coursera course this week, University of Arizona’s Astronomy: Exploring Space and Time. Here are some informal impressions from the first week:

  • This is my first Coursera course, so right now I’m not sure what to attribute to this particular course and what to attribute to Coursera as a whole. I’ll err on the side of discrimination and assume these are characteristics of the individual course.
  • A major problem to address in designing courses is the difference between thinking about the course and thinking about the content. We want to minimize how much time students have to think about the details of the course administration — deadlines, where material is located, etc. — and emphasize thinking about the content itself. For this course, there is certainly a learning curve with regard to navigation, but the course has thus far done a good job of attempting to lay out a fairly clear path. Of course, that’s a bigger challenge to do week-to-week than just at the beginning, so we’ll see how it develops.
  • The course is gated and synchronous. In other words, content is released on a schedule, and there are deadlines throughout the course rather than a more open-ended and self-paced approach. On the one hand, from my involvement with courses administered at Georgia Tech, this is certainly more pragmatic: synchronicity helps with grading, allows peer feedback opportunities (which this class uses), and encourages ongoing interaction amongst students. However, it also creates artificial barriers to content, punishes both high- and low-achieving students by enforcing a certain pacing, and may not be feasible for many students due to real-world obligations and constraints. These are, of course, issues for all online courses to wrestle with, but it’s worth noting how they play in this particular course. I’ll be interested to see how some of Coursera’s on-demand Verified Certificate programs work.
  • I wrote about this more extensively in my previous blog post, but the nature of Coursera’s open communities creates some issues. In addition to those problems, the course has been damaged first by an incredibly rude student insisting on replying to every thread and dismissively mocking anyone who disagrees with him, and second by a student posting a cluttering number of links to articles with little follow-up or discussion. The first was dealt with quickly by Coursera, fortunately, but the second doesn’t really represent a problem that can be fixed by administration: there will always be gaps between polite conduct and actual rules, and I’m not sure what to do when someone falls in the gap between the two. Interestingly, many of the strengths I noted about discussion boards online earlier actually can become weaknesses in a more open classroom: when everyone can propose their own discussions, much more noise enters the fray, making it more difficult to find those topics that will appeal to you individually.
  • A common criticism among MOOC critics is that MOOCs are good at replicating lecture-style college classes, but that lecture-style classes aren’t the goal. I see that at play strongly in this class. As far as a lecture-style class goes, the class is excellent: the presenter is pleasant, explains things very nicely, and has — at least so far — constructed the class with a good, natural pace and ordering of topics. At the same time, however, the lessons are most certainly lectures: the vast majority of the recorded video is spent looking at him, and the majority of visuals are static. There are some well-placed video clips, but it’s very easy to see a near-direct translation of this course to a traditional lecture-based college classroom. There are lots of animations, interactive activities, and more that could have nicely complemented the lessons and leveraged the opportunities presented by doing this class online, but so far it stays at the level of lectures.
  • I would be remiss to note the above without also mentioning the cost: those types of interactive exercises, innovative presentation styles, and extra resources cost money to develop, and the free nature of Coursera courses makes that difficult. Given how little the course costs, the course is absolutely amazing. There are certainly a lot of great things that could be done to make the course even better, but there would be a significant cost associated with them.

That last point is a good, succinct reflection of a portion of my present attitude toward online education. Many online educational platforms, especially Coursera and edX, emphasize, in my opinion, open-access. The top goal for these services is access to the material. That’s a fantastic mission, and I’m thrilled that great groups are pursuing this. At the same time, I strongly feel that online education has another opportunity: to do education incredibly well. Through things like automated feedback and tutoring systems, big data to uncover common misconceptions and errors, and polished, pedagogically sound instructional environments that can be mass-deployed much more cheaply than professional development, the internet can bring a different kind of educational revolution.

Of course, I’ve ignored the elephant in the room, which is assessment and feedback — that’s simultaneously the most important element of the educational experience and the hardest to replicate at scale with an open audience. In the first week, the only assessments were a pair of short multiple choice quizzes, but greater assessments are coming next week, so I’ll hold my thoughts on that for now.

As always, in the interest of full disclosure: I work for Udacity, so one could always argue that any criticisms I have of Coursera are inspired by my own biases toward my company. I don’t regard Coursera as a competitor for us at Udacity, though, for the reasons stated in the final point above.



Share on Google+Share on FacebookTweet about this on TwitterShare on LinkedInShare on RedditPin on PinterestEmail this to someone

MOOCs and online agendas

During my first week in one of the Coursera MOOCs I’m taking, University of Arizona’s Astronomy: Exploring Space and Time, I observed something rather interesting in the community portion of the course. At first I was going to simply include it in my first week impressions, but it brings up a bigger issue that I think is worth examining more thoroughly.

I don’t want to go into the details of it, but early in the course, a thread sprung up started by someone claiming the earth is only 6,000 years old. Obviously, this claim has no place in a science class. While the claim was brought informally by saying, effectively, “Here’s what I think, how about everyone else?”, the responses that followed took, in my opinion, an evangelical turn.

The broader issue at play is this: when we teach a course in person, we tend to assume that the majority of people in the class are students whose primary “agenda” for the class is to either learn the material or get a good grade. In my ten years in academia, I can’t think of an instance of ever worrying about whether additional agendas were at play. This is largely because of the major obstacle to participation in an in-person college degree program: you’re paying a ton of money and dedicating an enormous amount of time, which would deter people with more subtle agendas.

In Coursera and other MOOCs, however, anyone can join, and for free. What is to deter competing agendas from entering the fray? In these MOOCs, there will be people who sign up and participate in these courses with agendas rather than to learn from the course’s stated purpose. There will be churches that consider it an act of evangelism to try to educate these people studying the origins of the universe on the earth’s “true” origin. There will be special interest groups that see classes on climate change or other environmental issues as opportunities to change the conversation in their favor or sow doubt when no doubt ought to exist. There will be political organizations wanting to present a biased view of history that is favorable to their platform. These MOOCs risk becoming battlegrounds rather than learning opportunities. We see this already on other social media platforms, where teams of people are paid by particular groups to try to sway the conversation in one way or the other; there is no obstacle that I can see to prevent open online courses from being subjected to the same kind of astroturfing.

When we think of college courses (or at least when I do), we think of them as opportunities for groups of learners to explore a topic together, typically guided by an expert in the field. When people are entering these courses with their own agendas that directly conflict with the material of the course, that opportunity is compromised.

So what do we do about this? I’m not sure. One could argue in favor of a heavy-handed approach, that anyone arguing for pseudoscience or false science in a college science course is simply kicked out; but the targets of that heavyhandedness would likely take this as a sign that science fears their alternate viewpoints and would sooner silence them than engage them in discussion. Those political groups would insist that it is we scientists who are concealing an agenda in our MOOCs. That is, of course, not the case; but an introductory science course is not the place to get into debates with people that have no intention of ever changing their viewpoint. Complicating matters further, though, is that for some of these people, their participation in these MOOCs is earnest: for many, this may be the first time they’re exposed to the scientific process, and they are willing to learn, and if we merely dismiss them as another fundamentalist with an agenda we miss the opportunity to introduce them to a broader view of the world.

So, a heavyhanded response is likely not the best option. Do we engage them in authentic discussion? That is a risky endeavor. For one, engaging in a discussion with completely unsubstantiated viewpoints risks giving them undeserved legitimacy. For another, any authentic discussion depends on both parties discussing on the same grounds; if we disagree on fundamental truths, then we may not ever meet a resolution. If we debate with someone who does not understand or believe the nature of evidence and theory-building, there is no shared understanding that can arise. It is a waste of our time and a needless distraction for the class.

If both shutting them down and engaging them in discussion are undesirable, what then can we do? Right now, my only idea is a third option: attempt to prevent them from entering the class in the first place. Of course, we can’t and shouldn’t do “interviews” for admission to a class for the same reasons stated above, but there are other ways that we can limit the participation of people with little desire to actually authentically learn. The first to come to mind for me is to introduce a barrier to entry. Attach a cost to pushing for your agenda. When anyone can “walk” in and start spouting off with their views as if they are as qualified as the professor, it is unsurprising that we get people promoting their views rather than engaging with course content. If a cost is associated with doing so, I would argue you limit the number of people who enter with an agenda rather than the desire to learn. Of course, this introduces the side effect of potentially preventing authentic learners from joining the class as well; however, we know that paying students are already far, far more likely to complete courses anyway. Depending on how you explain this data, this would mean that either those students who no longer join when there exists a price were not likely to complete the course anyway, or that forcing those students to pay will increase their likelihood of completing the course. Either option is desirable, though it is up for debate whether those would be the actual effects.

This isn’t all or nothing, of course. One could imagine a hybrid model where the payment associated simply gets you access to the community features, but that the content is available for free. This would preserve Coursera’s MOOCs’ desired openness while also attempting to safeguard its courses from outside influences. And, as a happy side effect, the money raised through this mechanism could go toward funding the classroom experience, paying for graders, compensating professors for their time, and building up the platform. I know I’d be very curious to see how the community for this class operated if I had the option of only interacting with those students also paying to participate in the course.

Share on Google+Share on FacebookTweet about this on TwitterShare on LinkedInShare on RedditPin on PinterestEmail this to someone

Beginning a Course: Astronomy: Exploring Space and Time

It occurred to me a few weeks ago that, after completing my dissertation defense, I am — for the first time in my life — not presently working toward my next educational achievement or milestone. And that, to me, is absolutely unacceptable.

So, starting today, I’m taking my first Coursera course: Astronomy: Exploring Space and Time. I have three goals in mind here:

  1. To achieve a more complete view of online education, I want to explore the different major players. I’ll be completing a Udacity Nanodegree credential in the near future, as well as exploring edX and others.
  2. To keep my sanity, I want to continue working toward new educational milestones. I’m a firm believer in the growth mindset and its criticism of external motivators, but I’m also a firm believer in clear indicators of progress. It’s certainly possible to learn outside of a formal course like this, but it’s often difficult to monitor progress in the same way. A course to complete and a verified completion certificate can serve as a check that progress really is occurring.
  3. Astronomy has always been one of my unexplored passions, and I’m looking forward to finally having a venue and motivation to explore it!

I’ll post my impressions both of the course and of the platform as a whole as the course goes on. I’ll be doing the Verified Signature track as well, and it will be interesting to see how much rigor and reliability the track adds to the otherwise open program.

Share on Google+Share on FacebookTweet about this on TwitterShare on LinkedInShare on RedditPin on PinterestEmail this to someone