Improving Science Teaching in Victorian Schools

There has been much commentary in the paper recently about Australia’s falling standards in science and mathematics. Like most long-term problems this one has a built-in structure that is self-perpetuating.  This causal loop diagram shows the simple but entrench structure that is creating this problem.

The low quality of science teaching in schools produces students who are not well trained in science. This in turn means that the students entering teacher education programs are not well schooled in science. This leads to a dearth of good science teachers and the decline in the standards of science teaching. This cycle continues year after year and it is likely that the standards are continuing to decline.

The causal loop diagram demonstrates that there are two leverage points. The first is to improve the quality of the existing science teachers through extensive and intensive in-service training. The second is to pay a premium to school leavers go into teaching with strong qualifications in science.

If the goal of the second policy were to place two outstanding science teachers in every school in Victoria, there would need to be 5600 science-specific graduates.  The Victorian teacher education system produces 4200 graduates each year. So, if approximately half the intake per year were 1000 graduates  devoted to science teaching, it would take approximately 6 years to produce the necessary number of excellent science teachers. Unfortunately, if current trends continue, it can be expected that 30% of these will leave in the first five years, so the net long-term gain per year is likely to be closer than 600 per year. This means the realistic lead-time for improving science teaching is around 10 years. Sadly, this is probably beyond the concentration span of most state governments.

This sobering statistic highlights the increasing importance of retaining teachers in the profession, particularly those who are well trained and talented. However, it also highlights the huge potential of improvements in retention rates  for improving the quality of science teaching.

Why we can’t win the war on drugs.

It is a truism of systems thinking that sustainable systems generate their own behaviour.  In a technical sense this means that there are  positive feedback systems they keep the system working. This is particularly true in the drug trade.

The first important dynamic is the way the supply of heroin maintains the stock of heroin in any given community. This dynamic is classic supply and demand. As the supply of heroin increases, the stock of Heroin in the hands of drug dealers increases. This in turn sends the price down and the supply slows down as result. But when the supply slows down the heroin stock declines and the price rises again. Generally speaking there will be an equilibrium in this dynamic. The other part of the dynamic is the seizure of large shipments of heroin by the authorities.  These seizures decreased amount of heroin available in the market driving the price up and increasing the supply. Most of us do not realise how well organised the logistics of  this industry are. Seizures of drugs have little effect other than to put the price up in the short-term

However, there is a consequence of the price going up which is shown in the next loop. The price rise leads to an increase in petty crime: house burglaries, car break-ins, shoplifting etc. These small crime waves are often met by a spate of arrests on the part of the authorities who generally bundle the addicts off into the local jail. The absence of the addicts from the street leads to slight decline in use and an oversupply of heroin in the market. The fact that convicted drug addicts tend to be able to get drugs in jail is not something that civil authorities spend much time thinking about.

There is a final dynamic in this loop. It’s called marketing in this diagram and represents what drug dealers do when they have small amounts of drug  that they cannot sell. They simply give it away to a non-addict in the hope that it will become habit-forming. if this strategy is successful, it replaces the jail  addict with a new addict. Remember, the old addict is probably still using heroin in jail, so the total consumption of heroin is probably gone up as a result of this.


The logic of this diagram indicates that the war on drugs does nothing more than to put fluctuations into the price of heroin. But these fluctuations, and, as a result the increases in price, increase the crime rate.

The policy levers that have been used until now have been punitive ones: the seizure of drugs and the arrest of people in the drug trade. These policies seem to have done little to solve the problem of drug-taking in our community.

There are actually two other leverage points and this system that can be used. The first is to reduce the number of addicts. There are two ways of doing this as the stock flow diagram shows. The first, and most conventional one is to turn addicts into ex-addicts normally through programs such as the methadone programme.

The other, and much more difficult approach is to stop the flow of new addicts. This means addressing a wide range of social problems. It is a general truism that solving a problem normally takes as long as it took for the problem to develop. So this will be a long and necessarily costly process.

Which brings us to the other leverage point: The price of heroin. If heroin were to be legalised, the government could control the price. It would also be able to collect tax revenue from the sale of heroin and use that to fund rehabilitation projects. It would also be possible for the government to set a price well below that of the current illegal price.

These solutions are not perfect but they provide a better alternative than the “war on drugs”