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The "File Drawer Problem" and Tolerance for Null Results

📄 Original study
Rosenthal, Robert 1979 Ganzfeld Era methodology

Plain English Summary

Imagine scientists only publishing their exciting findings while stuffing boring "nothing happened" results into a file drawer. That's the "file drawer problem," and this landmark paper tackled it head-on. Rosenthal invented a clever tool called the "fail-safe N" — a formula that calculates how many hidden, unpublished null studies would need to exist in those file drawers to wipe out a published positive finding. The numbers can be staggering: in one example, you'd need over 3,200 buried studies to overturn 94 published ones, and nearly 50,000 to cancel out 311. He proposed a handy rule of thumb for when results are sturdy enough to trust despite possible hidden studies. This formula became absolutely essential in parapsychology research, where every meta-analysis now uses it to argue whether cumulative evidence for psychic phenomena can survive the file drawer threat.

Research Notes

One of the most cited methodology papers in behavioral science. The fail-safe N became standard practice in meta-analysis and is reported in virtually every psi meta-analysis in this library (Radin 1989, Bem 1994, Storm 2010, etc.). Its limitations are central to the meta-debate about whether cumulative psi evidence is robust to publication bias.

Introduces the "file drawer problem" — the concern that journals publish the 5% of studies showing Type I errors while 95% of null results remain unpublished — and derives a quantitative solution: the fail-safe N (tolerance for future null results). Using the method of adding standard normal deviates across k independent studies, the formula X = (k/2.706)[k(Z-bar)^2 - 2.706] computes how many additional null-result studies would be needed to reduce a combined significance level to p = .05. Illustrated with interpersonal expectancy research: 94 studies require 3,263 null studies to overturn; 311 studies require 49,457. Proposes X >= 5k + 10 as a threshold for file-drawer resistance.

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📋 Cite this paper
APA
Rosenthal, Robert (1979). The "File Drawer Problem" and Tolerance for Null Results. Psychological Bulletin. https://doi.org/10.1037/0033-2909.86.3.638
BibTeX
@article{rosenthal_1979_file_drawer,
  title = {The "File Drawer Problem" and Tolerance for Null Results},
  author = {Rosenthal, Robert},
  year = {1979},
  journal = {Psychological Bulletin},
  doi = {10.1037/0033-2909.86.3.638},
}