How Science Works

Homeopathy

Structure

1. Choosing Treatments2. Medical Trials3. Homeopathy4. How Science Works5. Ethics (optional)

Choosing Treatments

• Take a few minutes to discuss with your neighbours what treatments you have used, or those you have seen on TV or read about, for poor health

Choosing Treatments

• Three ‘volunteers’ with lab coats to spread out in the room.

• Students are to take a ‘condition’ card and take turns asking the ‘doctor’ what treatment they would suggest.

Choosing Treatments

• Students, in small groups, match the ‘conditions’ with ‘treatments’.

• There may be disagreement – the aim is to promote discussion.

• Summarise with idea that in each case, treatments are chosen for greatest effectiveness.

Choosing Treatments - Extension

Which treatments should be offered (if any) in these cases:

• Facial scarring• Mild diabetes which the sufferer fails to

control by diet and exercise• Chronic back pain that is not life-threatening• A condition which we cannot cure but where

life expectancy can be extended

Medical Trials

• New drugs may be based on traditional herbs, newly discovered compounds or be modifications of current treatments.

• New drugs are tested for safety and their effects on animals before humans try them.

• This provides hints towards safe, effective dosage for us.

Medical Trials

• We could simply give a patient a drug, record if they get better and then decide if it works or not.

• How well would this work?

• What are the problems?

Medical Trials

• For a fair test (and valid results) we need to make sure only one factor – the drug or treatment itself – changes.

• In practice, this means that we assign patients randomly to one of two or three groups andm if at all possible, keep their treatment secret until after the trial.

Medical Trials

• One group will receive the treatment being tested, for example a new drug.

• Another group receive a ‘placebo’ which does not contain the drug but appears identical.

• Often a third group will receive the ‘next best’ drug or the current recommended treatment.

Medical Trials

• Patients do not know if they are receiving the tested treatment because the placebo effect can produce a result when someone thinks they are receiving treatment.

• Medical staff should not know which treatment particular patients are receiving to avoid any deliberate or accidental bias.

Medical Trials

• Sometimes there is no placebo group because it would be unethical to withhold treatment for a medical condition.

• Sometimes trials are cut short if it becomes clear that the treatment is much better or worse than expected. (This happened with AZT, used to treat HIV and AIDS, in the ’80s)

Medical Trials

Randomised (patients are randomly assigned to different treatments) Control (treatments are compared to something else) trials or RCTs which are double-blind (neither patients nor doctors know what they are receiving until after) are the best way we have found to see the true effects of a treatment.

Medical Trials

• The more patients there are in the study, the more reliable the results are.

• If we measure the dependant variable (e.g. blood pressure) more carefully or in more detail, we say results are more precise.

• The more things we measure, the more likely it is that one of them will appear to show a change that is in fact random.

Homeopathy

• The Law of Similars– A chemical which causes a symptom will also cure

that symptom

• The Law of Infinitesimals– Diluting the chemical makes it more effective

• The Law of Succussion– Shaking the diluted liquid increases effectiveness

Hypothesis

Hypothesis

DataData

Analyse and DiscussAnalyse and Discuss

Experiment and Observe

Experiment and Observe

How Science Works

“It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong”

Richard Feynman

How Science Works

• Scientists have collected a lot of data over centuries of observation.

• We use the words accurate, precise, valid and reliable (among others) to describe the data. They are relative, not absolute terms.

• Scientists publish their data and methods in detail. Other scientists suggest improvements or carry out their own experiments.