Type M error
Definition: A Type M error occurs when a researcher concludes that an effect was observed with magnitude lower or higher than the real one. For example, a type M error occurs when a researcher claims that an effect of small magnitude was observed when it is large in truth or vice versa.
Related terms: Statistical power, Type S error, Type I error, Type II error
References:
- Gelman, A., & Carlin, J. (2014). Beyond Power Calculations: Assessing Type S (Sign) and Type M (Magnitude) Errors. Perspectives on Psychological Science, 9(6), 641â651. https://doi.org/10.1177/1745691614551642
- Lu, J., Qiu, Y., & Deng, A. (2018). A note on Type S/M errors in hypothesis testing. British Journal of Mathematical and Statistical Psychology, 72(1), 1â17. https://doi.org/10.1111/bmsp.12132
Originally drafted by: Eduardo Garcia-Garzon
Reviewed by: Mahmoud Elsherif, Helena Hartmann, Graham Reid, Mirela Zaneva