Expedition 2: How Do Scientists Know What Data to Gather?

February 3, 2016 Expedition 2

Last week we introduced the practice of developing and using models showing different ways the warrah might have reached the Falkland Islands. We will explore how Kit will be using models to help her decide what sorts of data she should collect while she is in the field.

First let’s talk about what mean by “models”

Models give us simpler ways to represent complicated situations or phenomena from the real world that we might not actually be able to see. Scientists use models as tools for “thinking with, making predictions, and making sense of experience.” Models also help scientists develop questions and explanations, and communicate their ideas and understanding to others (NRC, 2011, pp. 56-57). As you can see, models are involved with lots of scientific practices!

By now you are probably wondering, “What are some examples of models?”

Let’s keep in mind that models simply represent and explain “the real thing.” While we might think of a model as a physical replica like a globe used to model the earth, models exist in many different forms.

Some examples are:

  • diagrams,
  • physical replicas,
  • mathematical representations,
  • analogies,
  • mental models, and
  • computer simulations.

It is important to remember that since no model is exactly like the thing that it describes, all models have their merits (things they are good at describing), as well as their limitations (things they aren’t so good at describing).

Kit is using models too!

In order to help Kit answer her questions, she needs to find out more about what was happening in the Falkland Islands before Europeans arrived in 1690. Luckily, nature has ways of keeping historic records to help us understand the past without relying on human records.

We have seen Kit collecting columns of peat from several feet below the surface of the ground using a metal corer. As she explains, she is looking for evidence of charcoal within the layers of peat. Layers with more charcoal may indicate that humans had been building fires in the area, putting smoke or charcoal particles into the air, eventually falling back to the ground to be covered up by newer layers of material.

Using the peat cores as models of Falkland Islands history, Kit is able to focus on collecting data to tell her about the presence of charcoal. As Kit analyzes these data, she will have more evidence to be used to help her make claims about if humans might have arrived in the islands before European explorers. All those scientific practices are like puzzle pieces fitting together!

What do you think?

Here are some questions to discuss with your class, or to investigate on your own!

  • What were some of the models used by Kit in this video? What did they represent?
  • Why is she using more than one source of data?
  • How does the charcoal record increase her chances of finding evidence of people?
  • What part of her data collection are you most excited about (i.e. test pit survey, coring, bone dating)?
  • What models have you used before in the classroom? Outside of school?
  • Why are models important for both teaching and learning?
  • What might cause a model to change or be improved over time?

Have more questions?