Type I errors, also known as false positives, occur when you see things that are not there. Type II errors, or false negatives, occur when you don’t see things that are there (see Figure below).
Effect Size FAQs
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“The primary product of a research inquiry is one or more measures of effect size, not p values.”
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Effect Size FAQs 
This is a fantastic example of Type I and II errors! I’m a physician who teaches statistics to my medical students and residents. I’d like to use this image in a presentation: do you allow use for non-commercial purposes (with attribution of course)?
Feel free!
Thanks 😀