Field of Science

Changing exams

I just handed out a math assessment in my physical chemistry class, the same one I’ve used for the last several years. I generally don’t re-use exams (though I know colleagues who do), though I do re-use questions. By now I’ve been creating exams for more than a quarter of a century, and I wonder what the drift has been like over that time. How are the questions I ask now different (or not!) from what I asked 25 years ago? Or have the questions remained the same, and just the answers changed?

Fueling my introspection are the selections from the University of London’s 19th century bachelor’s degree exams. (H/T to a tweet from Nature Chemistry and the RSC). The chemistry question is one I could envision asking my students on an exam: “Explain the nature, from a chemical point of view, of the chief operations involved in the production of a photograph.”

The only catch, of course, is that the answer I’m expecting could be quite different than what the examiners in 1892 expected. In 1892, production of a photographic print necessarily involved silver, developers and fixing agents — and a darkroom. In 2011, production of a print could involve silicon and germanium, and a clean room. The theoretical underpinnings are less about pH and solution chemistry and more about semi-conductors and quantum mechanics.

What other reasonable exam questions might I ask, where the answers have changed so dramatically?

(And you have to love the example English question - just how important were werewolves in the 19th century?)

Photo of 39/365 Kodak Vigilant Six-20 Antique Camera, by M.Christian on Flickr.


  1. An economist returns to visit his old school. He's interested in the current exam questions and asks his old professor to show him. To his surprise, they are exactly the same ones he had answered 10 years before!

    When he asks about this, the professor answers, "The questions are always the same; only the answers change!"

    All over the net, e.g.,

  2. respected sir i want to follow your blogs how can do it ,help me please

  3. You could actually have two types of questions. One, like the example you have given, in which the topic (photography) is the same over the years but the technology to produce it has changed as science has advanced. Two, slightly different in my mind, is one in which our understanding of nature has advanced to provide a deeper understanding of a phenomenon. For the latter, I'm thinking something along the lines of: Explain the driving force behind the spontaneous expansion of a gas into vacuum (or the mixing of two gases or mixing of solutions). 120 years ago, the student would answer with classical thermodynamics and entropy. One could still answer that way, but a deeper explanation would involve statistical mechanics.

    Thanks for a great blog and a way to stretch my brain!


Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="">FoS</a> = FoS