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Do Aliens Live In Clouds? Evidence Based Belief

Posted by softestpawn on July 15, 2009

All day long we are told stuff: stuff that’s true, stuff that’s not, stuff that may be, stuff that’s ambiguous, stuff that’s incomprehensible, stuff that’s interesting, stuff that’s quickly forgotten. Stuff that might save your life. Stuff that might save your hair.

Sometimes it’s stuff that isn’t very important. Did you know, for example, that powdered fish scales are used to clear beer when it’s brewed? Unless you’re a beer-drinking vegan, you probably don’t really care if it’s true or not. Someone can tell you that in the pub and you can nod knowingly or look amazed or dispute it, whatever the social occasion, ego, company and number of beers consumed calls for, and sod the facts, And many of us enjoy aromatherapy or horoscopes without caring whether they really do what they say they will.

But if it’s stuff that’s important then such gossip, rumour and hearsay isn’t good enough. If it’s going to affect our job (is that really illegal?), or our relationships (is she really having an affair?) or our health (will bacon really give you a heart attack?) or our family (will vaccinations really hurt your children? Will not vaccinating them be worse?) or our future (will using fossil fuels really kill us all?) then we need better information.

This is the first in a series of how evidence can help tell us what to believe. It introduces the context and various principles in the paragraphs below, which link to more detailed explanations

So we might defer to authority; that is, we ask someone who is an expert on the subject and use their opinion.

This is a generally workable approach, but if we want more than opinion (expert or not), rumour and gossip then we need facts that are relevant: we need evidence. And we need enough evidence. Until then, it’s just a fantasy.

We need to be clear about what it is we’re trying to show, about whether in fact we can show it, and what that means to our idea.

We are rarely going to get “certain proof”, so we need to understand some ordinary things about uncertainty. It may be that some things are so uncertain that we shall just have to settle for not knowing.

Diversions are everywhere: If someone makes an extraordinary claim, it’s up to them to find evidence to support it, it’s not up to you to find evidence to disprove it. It’s not up to you to provide a workable alternative. And a rubbished alternative doesn’t make the original claim right.

As new evidence arrives, we need to understand how it supports (or contradicts) either a new link in a chain of reasoning, or confirms (or contradicts) existing evidence. We need to check that it is actually new; that it’s not just the same facts wearing a different face.

Most of all, throughout what can sometimes be an eye opening, invigorating and mind-blowing exploration of all this information, we must be careful not to introduce our own bias; that we don’t put our opinion before the evidence, and especially that we collect only the evidence that fits our initially ignorant opinion.

In the end, when someone tells us that “Aliens live in clouds!!”, and it’s important for you to know, then our response is not “That’s silly, because…” but:

“Oh yes? Show me!”

In the meantime, we don’t know if aliens live in clouds, but we have no reason to think so.

And that’s alright.

(With thanks to the badscience discussion forums)

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4 Responses to “Do Aliens Live In Clouds? Evidence Based Belief”

  1. endlesspsych said

    A decent book on probabilistic reasoning, statistics and the like would probably (ho ho) address most of the points raised. Unfortunalty given the nature of the subject matter I’m not sure that a “decent” book does exist.

    Also surely by collection bias you actually mean confirmation bias?

  2. endlesspsych said

    Also science isn’t certainty. It’s just as near as dammit as we can get with whatever paradigms we have at any given time.

    We never know for sure if aliens live in clouds or not, we never know for sure if global warming is man made… etc etc

    However with a knowledge base created by following the scientific method we will eventually have a very good idea.

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