Replicability-Report for JOURNAL OF EXPERIMENTAL PSYCHOLOGY: LEARNING, MEMORY, AND COGNITION

The Journal of Experimental Psychology: Learning, Memory, & Cognition (JEP:LMC) is published by the American Psychological Association (APA). The journal started publishing articles in 1982.

SCImago ranks JEP:LMC as #78 of all psychology journals with an SJR-Impact-Factor of 1.8 in 2014. At present, the replicability-report is based on articles published from 1998 to 2015. During this time, JEP:LMC published 2,029 articles. The replicability-report is based on 1,667 articles that reported one or more t or F-test in the text of the results section (results reported in Figures or Tables are not included).  The test-statistic was converted into z-scores to estimate post-hoc-power.  The analysis is based on 12,345 z-scores in the range from 2, just above the 1.96 criterion value for p < .05 (two-tailed), to 4.

PHP-Curve JEP.LMC

Based on the distribution of z-scores in the range between 2 and 4, the average power for significant results in this range is estimated to be 71%. This estimate suggests that 71% of the published significant results in this range are predicted to produce a significant results in an exact replication study with the same sample size and power (results with z > 4 are expected to replicate with nearly 100%).

The same method was used to estimate power for individual years.

PHP-Trend JEP.LMC

The results show a decrease over time. In the past 10 years, 8 out of 10 replicability scores have been below the historic average. The replicability score in 2015 was 70%, which is a high score relative to other journals, but below the 80% standard recommended by Cohen.  Given the small sample sizes in JEP:LMC, it would not require a lot of extra resources to boost the replicability of results reported in JEP:LMC.

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