Reply to post: Re: Cargo Cult Science

fMRI bugs could upend years of research

Alan Brown Silver badge

Re: Cargo Cult Science

"Except you don't. You assume that the scales and thermometers are accurate. "

I don't. I was brought up with the notion that you CHECK their calibration against known standards, which are in turn crosschecked against other standards and you periodically RECHECK the devices to ensure they have not gone wonky. You also need to know their limitations - thermometers being one example where they may be accurate in liquids but not in air.

I was also taught the difference between RESOLUTION and ACCURACY.

What that means is that an uncalibrated device can often tell you that there is a difference between two measurements to a high degree of resolution, but you can't tell what the absolute values really are. both are useful traits. A calibrated device which has low resolution might give an accurate reading for measurements, but the higher resolution uncalibrated device allows you to tell the differences between the readings (for this reason, a digital multimeter might give 3-4 digit resolution but the reading should never be considered accurate to more than 1 significant place even after calibration - nonetheless, it's still useful to have those extra digits when tuning for peaks or minimums.)

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