SIGNIFICANCE LEVEL By N., Pam M.S. - April 13, 2013 Null hypothesis significance testing. the probability of rejecting the null hypothesis when it is true. The probability of a type 1 error. also called alpha level. SIGNIFICANCE LEVEL: "The significance level is the probability of making a type 1 error." Related Psychology Terms BETA LEVEL RISK LEVEL NONCENTRALITY PARAMETER NULL HYPOTHESIS SIGNIFICANCE TESTING (NHST) T TEST ALTERNATIVE HYPOTHESIS DECISION RULE TYPE I ERROR BETA LEVEL TYPE II ERROR Cite this page: N., Pam M.S., "SIGNIFICANCE LEVEL," in PsychologyDictionary.org, April 13, 2013, https://psychologydictionary.org/significance-level/ (accessed May 11, 2021).