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

[jrtom.livejournal.com]

So... 12:48:

(1) The seasons are caused by Earth's axial tilt: between the spring and fall equinoxes, the northern hemisphere is tilted towards the sun, causing the amount of light falling on the northern hemisphere to be greater than that falling on the southern hemisphere. The reverse is true during the other 6 months of the year.
(12:53)

(2) Pluto is not currently considered a planet by astronomers; this is a recent change. In 2006 'planet' was first formally defined by the IAU to be something that orbited the sun, was essentially spherical, and cleared its orbit of debris; Pluto does not satisfy the third criterion and is therefore called a 'dwarf planet'. As of 11 June 2008, Pluto (and other dwarf planets outside Neptune's orbit) are now a class of their own, called 'plutoids'.
reference: http://en.wikipedia.org/wiki/2006_definition_of_planet
(12:58)

(3) [Skipped. This question doesn't make a lot of sense to me. "Discuss the relationship between the phenomenon known as "the greenhouse effect" and the ozone layer" would make more sense, but "compare and contrast" implies that they're the same kind of thing or phenomenon, and they're not. It's sort of like being asked to compare and contrast "inflation" and "the money supply".]

13:01
(4) The same reason anyone who's falling feels weightless: the force due to gravity is not being opposed by any other force, and there's not enough tidal effects (differential acceleration on different parts of their bodies) for them to be able to perceive such effects. They're falling in an essentially circular trajectory around the planet. (The question of why their trajectory is circular is a separate one; for that one, insert more quarters. :) )
13:06

Side point: I type probably in excess of 70 wpm, so you may want to factor that in.

[zandperl.livejournal.com]

Lots of people have been complaining about that third question. When I teach a class where I have that question, I usually make it clear in the course of the lecture what I mean. I'm planning to give my answers to all four questions on Monday in case people are curious.