Advice: Online quizzes

[asterroc]

So this summer I'm prepping to teach my first online course (to be offered either in Fall 2008 or Spring 2009). In my face-to-face courses I give an open-book timed essay quiz every week, partially to make sure the students are staying on track with their readings, and partially to prep them for closed-book exams. In the online version I will be dropping the closed-book exams and putting more weight into the quizzes, so it's important to me that I do them right. The course I am currently working on is basic astronomy, but if it goes well I will likely work on making other courses available in online versions as well.

The part I'm agonizing over is how much time to allow for the online versions of the quizzes. The problem is that some people will know how to touch-type and therefore will finish faster than they would in a face-to-face quiz, while other students will be hunt-and-pecking and will therefore take longer.

So in addition to just wanting general feedback from you, I'd appreciate it if you'd answer a couple questions that I could give on a quiz (each would be a whole quiz itself, the students would have 20 minutes in a face-to-face class) and tell me how long it took you to do from starting reading the question to finishing the answer. Feel free to use any resources you like for these, including your own textbooks, your own notes, or the internet, just answer in your own words. I don't care if you get these right or not, I'm looking more at how long it takes you to think about them, type them up, and then decide you're done.

Thanks!


1) Explain the cause of the seasons.





















2) Is Pluto currently considered a planet by astronomers? Why or why not?





















3) Compare and contrast the Greenhouse Effect and the Ozone Layer.





















4) Why do astronauts in the Space Shuttle experience weightlessness?




















Thanks for taking the time to answer a couple or all of these, and jotting down how long it took you to answer. And for any other feedback you may have.

X-posted

Comments

[framefolly.livejournal.com]

10:33, started reading. Wow. It's been over 10 years, I think...

1) Explain the cause of the seasons.
The earth revolves around the sun; every full revolution is a year. The earth also rotates on its own axis; every full rotation is a day. These two motions do not occur on the same plane (I wish I could draw a picture!) Because of this difference, for half the year the Northern hemisphere has longer days (more time exposed to the sun) and the other half the year the Southern hemisphere has longer days. Those are the respective summer seasons for the hemispheres. The other seasons also correspond to the relative lengths of daylight for the hemispheres.

10:42

2) Is Pluto currently considered a planet by astronomers? Why or why not?
No, I think, because I heard about it in the news. Okay. More serious answer requires some wiki-ing...
In 2006, the International Astronomical Union (IAU) updated its definition of planets. Pluto fits the first two criteria -- it revolves around the sun and is a sphere by its own gravitational force, but it fails to meet the third and final criterion, which is to clear the neighborhood around its orbit. Recent discoveries have shown that Pluto is one of many similar objects in a region called the Kuiper Belt. In order to account for Pluto and the other objects like it in the region such as Eris and Ceres, the IAU created a new classification called the "dwarf planet." Thus astronomers do not currently consider Pluto to be a planet.

10:53. I got a bit carried away with the web search fun, learned some stuff I didn't know. If this had been a timed test I could have done it faster.

3) Compare and contrast the Greenhouse Effect and the Ozone Layer.
Okay, zandperl, I'm going to try to wing this one even though it's been...???
The greenhouse effect is like what happens in a greenhouse, except on planet-scale. Light energy enters a transparent or translucent medium that encloses a space, like glass (in a greenhouse) or the atmosphere (of the earth). As it bounces off stuff, some of the light energy re-exits the medium, but some of it is converted into heat energy, and is trapped by the medium. That's why I always open my car windows a crack when I park it out in the AZ sun, because if I think the ambient outside temperature of 110+ is bad, I don't want to make my car into a greenhouse to compound the effect. Okay. It's late and I'm punchy. Scratch that. The ozone layer is a part of the earth's atmosphere, and therefore a part of the medium that makes the greenhouse effect possible. I don't know how else to compare or contrast (name the similarities and differences) between the terms, because they're not really like apples and oranges to me, but more like apples and apple juice...If I had to describe the ozone layer better than this to answer the question I'd have to look stuff up, which I'm too lazy to do right now.

11:01

4) Why do astronauts in the Space Shuttle experience weightlessness?
As the shuttle gets farther from earth (and not yet close to any other big object), earth's gravity exerts a lot less pull on it and everything within it. Weight is what we feel when we're moving our masses within and against the force of the earth's gravity. Astronauts in the space shuttle experience weightlessness because they are contending with a negligible fraction of the force of gravity that we experience on the earth's surface.

11:05

Do I pass, teach? Go easy on me -- I haven't taken your class!