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    Path to Science

    Thinking Dictionary

    Facts vs values

    What it is

    A factual claim is a statement that could, at least in principle, be checked with evidence. It doesn't have to be true. "The Moon is made of cheese" is a factual claim. It is simply false.¹

    A value, or opinion, is a judgement about what is good, what matters, or what should happen. "We should protect the Moon from mining" is a value. Evidence can inform it, but evidence alone can't settle it.

    Many arguments mix the two. Sometimes people present a disagreement about values as if it were about facts, or the other way round.

    Why it matters

    If you know which parts of an argument are factual, you know where evidence can help. If you know which parts are about values, you know where you'll need to discuss priorities instead.

    People find this harder than you might think. In a large US survey of more than 5,000 adults, people were shown five factual and five opinion statements and asked to sort them. Most got at least three of each right. The researchers said that was only a little better than guessing. About a quarter got most or all of them wrong.¹

    Politics made it harder. People on both sides were more likely to call a statement "factual" when it supported their side. For example, the statement "raising the minimum wage to $15 is essential for the economy" is an opinion. Yet 37% of Democrats labelled it factual, compared with 17% of Republicans.¹

    Taking an argument apart

    Here is an example of how a debate mixes facts and values.

    "Should our town build a wind farm on the hill?"

    • Factual parts: How much would it cost? How much electricity would it produce? How many birds might it harm? How would it affect house prices? Evidence can answer these.
    • Value parts: How much do those costs and harms matter, compared with the benefits? How much do we care about the view? Evidence can't settle these. People have to weigh them.

    Separating the two doesn't end the argument. But it shows where to look for evidence, and where to talk honestly about what matters to each person.

    When good goals pull against each other

    Many real choices involve a trade-off: getting more of one good thing means accepting less of another. It is rare for one option to win on everything. Even doing nothing has downsides.

    Drinking water is a clear example. Adding chlorine kills germs that cause disease. But it also creates small amounts of other chemicals, called by-products, and some of these could be harmful. The World Health Organization weighs the two risks openly. It judges the risk from by-products to be extremely small compared with the risk of water that isn't properly disinfected. So it advises that disinfection should not be weakened just to reduce by-products.² Removing one risk can add another, so "zero risk" is rarely on offer.

    Medical tests involve a trade-off too. Making a test stricter catches more real cases but raises more false alarms, as the False positives and false negatives entry explains. Scientists face similar choices about how to present their findings.³

    Facts can describe what each option gains and loses. How much each gain or loss matters is a value judgement. Seeing this can turn "the other side is wrong" into "the other side weighs things differently."

    In everyday life

    • Politics. "Taxes are too high" is a value. "Taxes rose by 2% last year" is a factual claim that can be checked.
    • Health. "This vaccine reduces hospital stays" is a factual claim. "Everyone should be required to get it" includes a value.
    • Family decisions. "This school has smaller classes" is checkable. "Smaller classes are worth the longer drive" is a value.

    The common trap

    The first trap is thinking "fact means true, opinion means false." A false claim can still be a factual claim, because it can be checked.

    The second trap is thinking "values are just personal taste, so there's no point discussing them." Values can be discussed with reasons. They just can't be settled by measurement.

    The third trap is believing that your side states facts while the other side states opinions.¹

    Some ways out:

    • For each statement, ask: "Could evidence settle this?"
    • Split mixed statements into a factual part and a value part.
    • Notice when you're quicker to call something a "fact" because you agree with it.

    Try it

    Pick a heated topic, such as speed limits in cities. Write down six statements people often make about it. Label each one: factual claim, value, or mixed.

    For each factual claim, write down what evidence would settle it. For each mixed statement, split it into a fact part and a value part.

    Related concepts

    Scenario planning · Misinformation vs disinformation · Confirmation bias · Credible sources · Scientific uncertainty · False positives and false negatives · Motivated reasoning

    Sources

    1. Mitchell, A., Gottfried, J., Barthel, M., & Sumida, N. (2018, June 18). Distinguishing between factual and opinion statements in the news. Pew Research Center. https://www.pewresearch.org/journalism/2018/06/18/distinguishing-between-factual-and-opinion-statements-in-the-news/

    2. World Health Organization. (2022). Guidelines for drinking-water quality: Fourth edition incorporating the first and second addenda. WHO. ISBN 978-92-4-004506-4. https://www.who.int/publications/i/item/9789240045064

    3. Mastrandrea, M. D., et al. (2010). Guidance note for lead authors of the IPCC Fifth Assessment Report on consistent treatment of uncertainties. IPCC. https://www.ipcc.ch/site/assets/uploads/2017/08/AR5_Uncertainty_Guidance_Note.pdf