I am a developer or contributor to several open source software projects.

psychmeta icon

psychmeta: Psychometric Meta-Analysis Toolkit

Jeffrey A. Dahlke and Brenton M. Wiernikh

psychmeta is an R package for running psychometric meta-analyses developed by my colleague. Currently, the package can compute barebones, artefact-distribution, and individual-corrections meta-analyses of correlations and d values (standardized mean differences). psychmeta can correct for measurement error, range restriction (direct or indirect), dichotomization, and scale coarseness in one or both variables. It provides many tools to make conducting meta-analyses more efficient and replicable by automating many of the steps of the meta-analysis process. psychmeta also includes tools for preparing and cleaning data for meta-analyses (e.g., converting effect sizes, computing reliability coefficients and range restriction ratios), conducting sensitivity, moderator, and follow-up analyses, and preparing results for presentation or publication.

psychmeta is available from CRAN and GitHub. Please report any bugs, errors, or feature requests on GitHub.

OPMA logo

Open Psychometric Meta-Analysis in Excel

Brenton M. Wiernik

Open Psychometric Meta-Analsyis in Excel (OPMA) is a program to conduct psychometric meta-analyses of correlations in Excel. It is designed to be easy to use for non-programmers. OPMA can correct for measurement error in both variables and direct or indirect range restriction in one variable.

OPMA is available from GitHub. Please report any bugs, errors, or feature requests on GitHub.

Zotero logo


Center for History and New Media, George Mason University

Zotero is an open-source software program for collecting, organizing, and citing bibliographic and research sources. Zotero is particularly valuable for conducting systematic reviews and meta-analyses. I contribute to Zotero by writing documentation, writing code patches, programming citation style code, and providing user support.

I am also a developer or contributor for several Zotero plugins:

  • Zotero DOI Manager (Brenton M. Wiernik): A plugin to verify and clean DOIs stored in your Zotero database, as well as to automatically retrieve shortDOIs to make shorter citations.
  • Propachi (Frank Bennett and Brenton M. Wiernik): A plugin that enables APA-style capitalization of reference subtitles.
  • ZoteroQuickLook (Mikko Rönkkö with Brenton M. Wiernik): A plugin to enable QuickLook preview functionality in Zotero.

I’ve developed several CSL citation styles for my own use with Zotero (these styles also work with Mendeley, Papers, and other CSL programs).

  • APA (meta-analysis): This style allows you to indicate sources that were included in a meta-analysis in the references list. When using this style, add annote: * (or a character other than *, such as annote: a ) to the Extra field (Zotero) or the Note field (Mendeley) for items included in the meta-analysis. For other CSL programs, add annote: * to whichever field is mapped to the note CSL variable.
  • APA (short authors): This style shortens APA citations by using et al. for all citations with 3+ authors and never adds author initials or given names for disambiguation.
  • APA (numeric): This style uses numeric in-text citations (as in many physical science and medical journals) and gives APA style references in the bibliography.
  • Systematic Review Tables: A simple citation style for formatting citations to sources in a systematic review data table.

I’ve also compiled a set of scripts to use various popular search engines and databases with Zotero’s Locate feature. To add the ability to search for articles in Google Scholar, Google, Amazon, ProQuest, Unpaywall, and other search engines, download the engines.json file linked below. Open it and remove any lookup engines you don’t need, then save. Place the file in the locate folder in your Zotero data directory (replacing the version of engines.json that is already present).

  • engines.json: A list of useful search engines for Zotero’s Locate feature.