One of the first things that struck me when I started teaching is that science comes across as a difficult subject to a majority of the students. There are some to whom it seems to come naturally, and we label them “science-persons” while the others who seem to struggle, as “arts-persons” or “humanities-persons”.

While there is no denying that there are variations in children’s ability, aptitude and interests, I’m gripped by the question whether everyone can be given a meaningful and enriching, and not painful science education. And if so, what would that be like.

One of the approaches that could be taken, perhaps, is to study how science is normally taught and what are the sources of the difficulties which children face. How is scientific knowledge organised in our brains and what are the factors which make this process so difficult for so many? It might require some thought about the very nature of science and scientific knowledge.

While I’m not an expert in any of these areas, some of the problems which I myself have faced as a student provides some hints. The problem may not be such a big mystery if you look a bit closer.

Much of science is abstract, counter intuitive, and removed from real life experience. Take, for example, the kinetic theory of matter, which says that the particles which make up matter are in continuous motion and that the temperature of a body is a measure of the average kinetic energy of its particles. Most text books don’t explain why people came to believe that the particles are in motion, or why a body is hotter if the particles are moving faster. There is a lot that ends up having to be taken for granted.

This is not an isolated example- far from it. Every theory or topic that children have to learn has some gap like this, and after a while instead of the concepts building up nicely into a jigsaw puzzle- an understanding of the way the world works, they end up being isolated and unrelated fragments that have to be “mugged up”.

Related to this is the fact that scientific knowledge is often presented as absolute truth. Very little, if any importance is given to the process of discovery and the evolution of scientific knowledge. Text books do mention some history, but it is often lost within the vast sea of facts which children have to memorise. And in the process, only the end product, and not the evolution of the idea or the real life phenomenon that led to it, is given importance.

Another difficulty which students often face is in forming mental pictures or representations of concepts or processes. If you are unable to visualise it, it quickly becomes abstract, meaningless information.

For example, consider the case of common salt dissolving in water. I, the teacher, have a vivid picture of differently sized Na+ and Cl- ions packed tightly in the solid crystal, and water molecules floating (or flowing!) around with their partially positive H and partially negative O ends. And the moment you put NaCl in water, the partial charges of water molecules arranging themselves around the ions in the salt and pulling them apart. It is a complex mental representation, built up over time, with connections to many other concepts like kinetic theory, chemical bonding etc. How can a teacher help a student build her own mental picture? Some students do this effortlessly, but can the others do it with some help and more importantly, can having such coherent mental pictures help them learn science more easily and connect with it better?

Most text books would introduce this concept with a sentence like “Sodium chloride dissolves well in water because it is a polar solvent.” And then go on to beat around the bush with all kinds of irrelevant information. How does the student visualise the term “polar solvent”? Does she think about it at all, or switch off completely? Or does she memorise the term without any clue as to what it means and move on and write the correct answer during the exam?

It’s important to note that the problems I have mentioned are not solved by just doing “more practical work than theory”. The same problems arise in lab sessions also, because doing an experiment is one thing, and understanding what happens behind it is another. Of course, being usually more engaging than theory classes, there is a greater chance that the student will apply herself better and get the concept. But one cannot assume that the student has understood it just by carrying out the experiment.

Again, let’s take an example, say precipitation reactions where solutions of two soluble salts are mixed together to form an insoluble salt.

$Na_2CO_3 + CaCl_2 \longrightarrow 2NaCl + CaCO_3 \downarrow$

Some children are immediately able to connect the above equation to their understanding of ionic compounds and solutions. They will immediately conclude that calcium and carbonate ions can’t stay together in the solution and that’s why they precipitate, and if they had come across calcium carbonate in earlier experiments, they would already know that it is an insoluble salt, which all fits in nicely into a perfect mosaic of knowledge. They would already be predicting which other pairs of solutions would give precipitates.

But for most, the equation wouldn’t mean anything deeper than what it literally states, and it needs to be made explicit to them what all information it represents and a visualisation of the process that is taking place. Otherwise, it is not unlikely that many would do this particular reaction, learn the equation by heart, do the next one, again learn the equation by heart and so on.

It’s fortunate that I have had these problems myself as a student, especially during engineering days, so that I can connect with the difficulties which students face. It’s not as if only “non-science-persons” face these difficulties, and “science-persons” don’t face them at all. I, whom many would classify as a “science-person”, have had experiences of having gone through entire courses without being able to make out head or tail of what was taught, and having to mug up to pass the exams. The moment you are unable to form coherent mental pictures of a concept, it is going to become more and more meaningless.