Science changes

What do we mean by a ‘fact’ in science? Not much, really. The grounds of scientific understanding have been swept up from under the feet of generations of scientists as new research undermined previously held ideas. This is the way science progresses. Think Copernicus, Newton, Boyle, Lavoisier, Bohr. Instead of a pillar of fact, scientific knowledge is tentative, empirical, subjective, socially and culturally embedded, and relies on human inference, imagination and creativity. A ‘fact’ is just something we hold to be the best possible understanding of the scientific community with the information we currently have available.

This understanding of scientific facts has been reflected in the school curriculums for the last two decades. KS3 students are expected to ‘understand that scientific methods and theories develop as earlier explanations are modified to take account of new evidence and ideas, together with the importance of publishing results and peer review’. But despite this long history, talk in classrooms has often centered on talk about ‘facts’ and ‘truth’: in response to students’ incessant questions I have heard many exasperated teachers fall back on ‘it’s just a scientific fact’. And this is becoming increasingly necessary as curriculum time is being squeezed by an ever increasing number of ‘facts’ on specifications!

So, how can we help students grasp this tentative, revolutionary science, without compromising their ability to learn the ‘facts’?

1 Define a fact and banish ‘truth’

Explicitly defining what we mean by a ‘scientific fact’ and agreeing that terminology with the students can be extremely helpful. Assessing this understanding regularly through talk when discussing ‘facts’ helps embed this too. You can also ask students to question which facts they are learning are more likely to be overturned, eg the model of the atom is more likely to be overturned than the boiling point of water (given temperature is defined this way).

But beware of using the word ‘truth’. It is an extremely loaded term and brings much baggage that can really undermine the notion of science as liable to change. Better to give it a wide berth where possible.

2 Provide opportunities to develop ‘new’ theories

Many of the scientific changes students study are extremely abstract (the model of the atom and the development of the periodic table are prime examples). But students will understand scientific change better if they can grapple with it first-hand. Providing students with limited data and asking them to draw initial conclusions before further experiment and refinement is a powerful iterative process that reflects what we want them to learn and how the learning process works. This works particularly well when introducing new classes of compounds and asking students to spot patterns and theorise about their reactions. Matching the derived theory to the specification will ensure the correct ‘facts’ are the ones embedded in students’ long-term memories.

3 Evaluate different theories

• Is there enough data to support the theory?
• How well does the theory fit the data?
• Are there any anomalies and are these sufficiently accounted for?
• Does the theory fit with other scientific theories that are currently accepted?

4 Build in some philosophy of science