Assessment & Research

A microsoft excel(®) 2010 based tool for calculating interobserver agreement.

Reed et al. (2011) · Behavior analysis in practice 2011
★ The Verdict

Grab the free Excel file to auto-calculate nine IOA indices for any data set in under a minute.

✓ Read this if BCBAs and RBTs who check observer agreement and want a no-cost calculator.
✗ Skip if Teams already using purchased IOA software or Google Sheets-only workflows.

01Research in Context

01

What this study did

Kangas et al. (2011) built a free Excel file that calculates nine different inter-observer agreement formulas.

You paste your data, pick the formula, and the sheet returns the answer in seconds.

The tool works for both continuous count data and discontinuous time-sample data.

02

What they found

The paper is a how-to guide, not an experiment, so no new data were collected.

Authors showed that the same Excel file can handle total count, exact count, interval-by-interval, and six other IOA methods.

Step-by-step pictures are included so you can copy the sheet or build your own.

03

How this fits with other research

Morris et al. (2018) extends this idea by turning Excel into a full data-collection system with live graphs and dropdown menus.

Deochand et al. (2015) and Fuller et al. (2019) keep the Excel theme but move from numbers to visuals, giving easy ways to add phase-change lines and trend lines.

Lerner et al. (2012) uses the same Excel 2010 platform, yet focuses on delay-discounting graphs instead of IOA, showing the software can serve many behavior-analytic jobs.

Friedling et al. (1979) looks contradictory because it warns against trusting single IOA numbers; instead it plots a disagreement band so you can eyeball believability. The two papers actually pair well—use the Excel tool to compute the index, then use the 1979 plot to decide if the data are good enough.

04

Why it matters

Reliability checks eat time and mistakes slip in when you hand-calculate. Downloading this ready-made sheet gives you nine IOA formulas in one place and drops your report prep from minutes to seconds. If you later want prettier graphs or built-in data entry, the same Excel skill you used here sets you up for the newer templates from Morris, Neil, and Fuller teams.

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Download the Excel tool, paste last week’s reliability data, and confirm which IOA formula your funding source wants.

02At a glance

Intervention
not applicable
Design
methodology paper
Finding
not reported

03Original abstract

This technical report provides detailed information on the rationale for using a common computer spreadsheet program (Microsoft Excel(®)) to calculate various forms of interobserver agreement for both continuous and discontinuous data sets. In addition, we provide a brief tutorial on how to use an Excel spreadsheet to automatically compute traditional total count, partial agreement-within-intervals, exact agreement, trial-by-trial, interval-by-interval, scored-interval, unscored-interval, total duration, and mean duration-per-interval interobserver agreement algorithms. We conclude with a discussion of how practitioners may integrate this tool into their clinical work.

Behavior analysis in practice, 2011 · doi:10.1007/BF03391783