TY - JOUR
T1 - The Prevalence of Marginally Significant Results in Psychology Over Time
AU - Olsson-Collentine, Anton
AU - van Assen, Marcel A.L.M.
AU - Hartgerink, Chris H.J.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - We examined the percentage of p values (.05 < p ≤.10) reported as marginally significant in 44,200 articles, across nine psychology disciplines, published in 70 journals belonging to the American Psychological Association between 1985 and 2016. Using regular expressions, we extracted 42,504 p values between.05 and.10. Almost 40% of p values in this range were reported as marginally significant, although there were considerable differences between disciplines. The practice is most common in organizational psychology (45.4%) and least common in clinical psychology (30.1%). Contrary to what was reported by previous researchers, our results showed no evidence of an increasing trend in any discipline; in all disciplines, the percentage of p values reported as marginally significant was decreasing or constant over time. We recommend against reporting these results as marginally significant because of the low evidential value of p values between.05 and.10.
AB - We examined the percentage of p values (.05 < p ≤.10) reported as marginally significant in 44,200 articles, across nine psychology disciplines, published in 70 journals belonging to the American Psychological Association between 1985 and 2016. Using regular expressions, we extracted 42,504 p values between.05 and.10. Almost 40% of p values in this range were reported as marginally significant, although there were considerable differences between disciplines. The practice is most common in organizational psychology (45.4%) and least common in clinical psychology (30.1%). Contrary to what was reported by previous researchers, our results showed no evidence of an increasing trend in any discipline; in all disciplines, the percentage of p values reported as marginally significant was decreasing or constant over time. We recommend against reporting these results as marginally significant because of the low evidential value of p values between.05 and.10.
KW - APA
KW - marginal significance
KW - null-hypothesis significance testing
KW - open data
KW - open materials
KW - over time
KW - p values
UR - http://www.scopus.com/inward/record.url?scp=85062042298&partnerID=8YFLogxK
U2 - 10.1177/0956797619830326
DO - 10.1177/0956797619830326
M3 - Article
C2 - 30789796
AN - SCOPUS:85062042298
SN - 0956-7976
VL - 30
SP - 576
EP - 586
JO - Psychological Science
JF - Psychological Science
IS - 4
ER -