Tag Archives: EMSEA14

Conducting experiments at EMSEA14

Kristin’s and my workshop at EMSEA14.

As I mentioned before, Kristin Richter and I are running the workshop “Conducting oceanographic experiments in a conventional classroom anywhere” at the European Marine Science Educator’s Association Meeting in Gothenburg, Sweden. There is quite an active Twitter crowd around, so you can follow the storyfied meeting or look out for #EMSEA14 on Twitter.

Our workshop has been represented quite well there, too, so I’ll just post a couple of my own pictures here.


Final preparations: Kristin is mixing salt water


Watching intently the melting ice. As my former boss would say: It’s like watching paint dry.


Except that it is really fascinating and that there are so many things to discuss!


Kristin and I took turns presenting the workshops, which was great. Plus it was really nice to have two instructors walking around, talking to the groups, instead of just one.


Kristin talking about using our favorite experiment to practice applying the scientific method.

For further reading, here are our slides.

Plus there are a lot of post dealing with the exact same experiment after the cut below. And there are two more posts on this exact experiment coming up that are scheduled already, one tomorrow, the other one in two weeks time. And thanks to a very nice family of participants I already have plenty of ideas of how to modify this experiment in the future!

[edit: There finally is a picture of me in the workshop, too, to show that I actually did contribute and not just leave it all to Kristin:


So I did actually do something, too, and not just take pictures. Plus did you notice how there is a EMSEA sign on the podium? There were signs on the doors, too, both on the inside and outside, so one of them was visible even when the door was wide open. Such good thinking of the organizers! Gothenburg University does have a seriously impressive infrastructure in any case: Tables and chairs on wheels so the whole room could easily be modified to suit our needs. Awesome.]


Melting ice cubes reloaded

Or why you should pay attention to the kind of salt you use for your experiments.

The melting ice cubes in salt and fresh water is one of my favorites that I haven’t written about in a long time, even though (or possibly: because) I wrote a whole series about it last year (see links at the end of this post).

Now that the EMSEA14 conference is almost upon us and Kristin and I busy preparing our workshop, I thought I’d run the experiment again and – for a change – take the time to finally know how much time to schedule for running the experiment. This is the experiment that I have run most often of all in all kinds of classes, but there you go… Usually I have more time than just 30 minutes, and there is so much other content I want to cover in that workshop!

There are a couple of things that I learned running this experiment again.

  • It takes at least 10 minutes to run the experiment. My water was slightly colder than usual room temperature, my ice cubes slightly smaller, though. And those 10 minutes are only the time the ice takes to melt, not the time it takes to hand out the materials and have the groups settle down.
  • There is a reason it is always recommended to use kosher salt for these kind of experiments. Look at the picture from one of the old posts in comparison to the ones from today: The iodized salt containing folic acid I had in my kitchen dissolves into really milky water. I really should have walked the two extra meters to get the good salt from my oceanography supplies in the other room!

Ice cubes melting in fresh water (left) and salt water (right) – old experiment


Ice cubes melting in fresh water (left) and salt water (right) – experiment today

  • Some food dyes are the devil. My whole kitchen is red. Plus the ice cubes didn’t freeze nicely (for a post on ice cubes freezing from salt water click here), the ice chipped when I tried to get the cubes out of the ice cube tray. I definitely can’t have that mess at a workshop. So here is another argument for using non-dyed ice cubes! The more important argument being that you think more if the cubes are not dyed and you don’t immediately see the explanation…

But it is always a fun experiment to run, and there are always new things to spot. Watch the video below and see for yourself! (Explanations on the weird phenomena coming up in a future post!)

The links to the “melting ice cubes” series:

Ice cubes melting in salt water and freshwater (post 1/4)

Ice cubes melting in fresh water and salt water (post 2/4)

Melting ice cubes – one experiment, many ways (post 3/4)

Melting ice cubes – what contexts to use this experiment in (post 4/4)

Other posts on this experiment:

Dangers of blogging, or ice cubes melting in fresh water and salt water

Guest post: The mystery of the cold room

Why might students not learn from demonstrations what we want them to learn?

More potential pitfalls to avoid when showing demonstrations.

Kristin and I have been invited to lead a workshop on “Conducting oceanography experiments in a conventional classroom” at the European Marine Science Educators Association EMSEA14 conference in Gothenburg in October (and you should definitely come – it’s gonna be a great conference!). And while you know I’m a big fan of showing a lot of demonstrations and experiments in class, for the purpose of this workshop I’ve looked into the literature to base the argument for (or against) demonstrations on a sound scientific basis.

I recently discussed how demonstrations help most when they are embedded in active learning scenarios, where students make predictions before watching the demonstration, and discuss afterwards. But what else should we take care of when using demonstrations as a teaching tool?

The paper “Why May Students Fail to Learn from Demonstrations? A Social Practice Perspective on Learning in Physics” by Wolff-Michael Roth and coauthors (1997) presents 6 dimensions that might hinder student learning. Rather than repeating what they found from their example (but you should definitely read the paper – it is really interesting!), I thought I’d ask myself how well my own teaching is doing along those 6 dimensions.

So without further ado, let’s get started. These are the 6 dimensions:

1) Separating signal from noise
2) Different discourses
3) Interference from other demonstrations
4) Switching representations
5) Larger context of demonstrations
6) Lack of opportunities to test science talk

For 1 and 3, I immediately identified situations in my teaching where I might have hindered student learning by not paying enough attention to those dimensions. Those I will discuss in separate posts over the next couple of days (dimension 1; dimension 3). I am still thinking about 2 and 4 and while there are probably examples of where I could improve along those dimensions, I still haven’t come up with examples where the signal is a lot clearer than the noise (see what I did there?). So let’s focus on 5 and 6 here.

So, 5. “Larger context of demonstrations”? In their paper, Roth and coauthors mainly focus on how students are told that the demonstrations they see will not be relevant for the exam. This is definitely not the case in my classes – my students know that they might have to recall details of the experiments in the exam or use them as a basis to develop other experiments. Also most experiments in my class are not just presented, but are in some kind of teaching lab context, or are taken up in homework assignments. As one motivation for me to show experiments in class is for students to practice to write lab reports, the pen-dropping described in the article does not happen in my class, or at least not nearly as extensively as described.

However, I am wondering whether the students realize the larger larger context for the demonstrations. As in whether they realize the learning objectives behind me showing the demonstrations. This I need to think more about.

And 6. “Lack of opportunities to test science talk”? I have been using peer instruction in my courses, and I have always interacted a lot with my students, both during lectures, labs, student cruises and outside of classes, but I could probably still improve on this. Especially seeing the positive effect active learning has, I will make sure to incorporate enough opportunities to practice science talk in future courses.

How about you? How are you doing along those 6 dimensions?

Roth, W. M., McRobbie, C. J., Lucas, K. B., & Boutonné, S. (1997). Why may students fail to learn from demonstrations? A social practice perspective on learning in physics. Journal of Research in Science Teaching: The Official Journal of the National Association for Research in Science Teaching, 34(5), 509-533.