dr.ricky online

Tag: learning

  • Falsifiability

    Falsifiability

    In an earlier posting on detecting the signs of pseudoscience, I quoted an article which mentions unfalsifiability as a property. This is actually a pretty good early test for understanding if something is science-based, and attends to a common misunderstanding about the scientific process.

    Whenever the phrase “scientifically proven” is used, your critical thinking alarm bells should go off – because much of scientific progress is based on disproving things. Unambiguously proving a hypothesis is actually quite difficult and rare, but what happens more frequently is disproving the counter-hypothesis, because all you need is a simple break in the logic or a sample contrary to it. When a conjecture or concept withstands extensive attempts at disproof is when it enters the field as a major theory.

    Let’s try this out. Take the statement that “All cars have four wheels”. It’s kind of difficult to figure out how to prove this, but finding a single car that has three or five wheels is sufficient to disprove it. A single example of an object falling at a different acceleration rate would be sufficient to disprove what we know about gravity, or a single core sample of fossils forming at a different order would overturn evolution – but after hundreds of years of attempts, these theories have stood their ground. And good scientists continue to think about ways to show that something accepted as true may be false. Which is an important feature – falsifiability is key. And the failure of these tests add to our confidence in these major theories. If you cannot devise a test that will sufficiently disprove the statement, it’s likely outside of science, no matter what the trappings.

    Let’s look at an example of something which is unfalsifiable. This is taken directly from the product description page of VitaminShoppe, a prominent sponsor for the AVP (US domestic pro beach volleyball tour):

    Naturally detoxifies and boosts your immune system

    Can you think of a test that will falsify this statement? What kind of trial could be done to definitively show that something does not “boost the immune system” or “naturally detoxify”? Near as I can tell, this falls into the category of unfalsifiable, sort of like the claim that a machine detects ghosts. When evaluating promises made through coaching advice, improve your critical thinking skills by asking how you can falsify a statement. And this is how we progressively increase confidence in practice.

  • Vaccination Exemptions in the USA

    Vaccination Exemptions in the USA

    Vaccination Exemptions in the USA

    The United States Centers for Disease Control (CDC) publishes a Morbidity and Mortality Weekly Report, and in it they track the vaccination rates in different states for children enrolled in kindergarten, and an interesting table is the report on the rate of exemptions from vaccinations, as well as the reason behind it. Granted, different states have varying laws with regards to vaccination requirements, and some allow separation of the exception reasons between medical, religious and other philosophical reasons, which makes getting consistent data problematic. But we do have good data for the 2015–2016 enrollment, and the 2016–2017 enrollment.

    The reports themselves are straight tables, but data visualization helps in teasing out the meaning there.

    2016_2017_CDC
    Summarizing the CDC reports between 2015-2016 and 2016-2017 school years for the rate of vaccine exemptions among kindergarten students, divided by state. A number of states are excluded. Blue dots are for the earlier year, red dots for the data a year later. Note that for herd immunity, the general consensus is about 95% of the population should be vaccinated. The Y-axis displays the ratio between medical and non medical reasons given for the exemption. Note that with the exception of DC, all states have ratios below 1, which means that more people are seeking exemptions for religious or philosophical reasons than for medical ones. 

    This data is dense, but highlights some problematic states, like Oregon, which has an unusually high rate of vaccine exemptions, and most of them for non medical reasons. Let’s look at the trend from year to year.

    Change year
    The arrows point in the direction which portend better public health trends: a drop in the rate of exemptions, and an increase in ratio of medical to non-medical reasons. California and Vermont seem to be on the right track, but most of the country is actually inching in the wrong direction, with Nevada and Wisconsin leading the way. 

    Sadly, the antivaccinationist movement seems to be permeating the mindshare, just by manipulating doubt and exploiting parental concern. Non medical exemptions are a key to this degradation of our public health system.