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Reporting and interpreting non-signiûcant results in animal cognition research

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How statistically non-signiûcant results are reported and interpreted following null hypothesis signiûcance testing is often criticized. This issue is important for animal cognition research because studies in the ûeld are often underpowered to detect theoretically meaningful eûect sizes, i.e., often produce non-signiûcant p-values even when the null hypothesis is incorrect. Thus, we manually extracted and classiûed how researchers report and interpret non-signiûcant p-values and examined the p-value distribution of these non-signiûcant results across published articles in animal cognition and related ûelds. We found a large amount of heterogeneity in how researchers report statistically non-signiûcant p-values in the result sections of articles, and how they interpret them in the titles and abstracts. Reporting of the non-signiûcant results as <No Eûect= was common in the titles (84%), abstracts (64%), and results sections (41%) of papers, whereas reporting of the results as <Non-Signiûcant= was less common in the titles (0%) and abstracts (26%), but was present in the results (52%). Discussions of eûect sizes were rare (<5% of articles). A p-value distribution analysis was consistent with research being performed with low power of statistical tests to detect eûect sizes of interest. These ûndings suggest that researchers in animal cognition should pay close attention to the PeerJ reviewing PDF | (2022:05:73463:1:0:NEW 25 Jan 2023) Manuscript to be reviewed evidence used to support claims of absence of eûects in the literature, and 3 in their own work - report statistically non-signiûcant results clearly and formally correct, as well as use more formal methods of assessing evidence against theoretical predictions.



Animal behavior, Animal cognition, Negative results, Non-significant results, Null hypothesis significance testing, Statistical inferences, Animals, Research Design, Animal Experimentation, Cognition

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PeerJ Inc.
Biotechnology and Biological Sciences Research Council (BB/M011194/1)