CheckCell is a data debugging tool for Excel that finds errors or suspicious values.

CheckCell is efficient: the current prototype runs in seconds for most spreadsheets. We performed a case study by employing workers via a crowdsourcing platform, and found that CheckCell is effective at finding many data entry errors. In addition, CheckCell automatically found a number of problems (including this one) in the now-infamous Reinhart-Rogoff spreadsheet:

For example, Norway spent only one year (1946) in the 60-90 percent public debt/GDP category over the total 130 years (1880-2009) that Norway appears in the data. Norway’s economic growth in this one year was 10.2 percent. This one extraordinary growth experience contributes fully 5.3 percent (1/19) of the weight for the mean GDP growth in this category even though it constitutes only 0.2 percent (1/445) of the country-years in this category. Indeed Norway’s one year in the 60-90 percent GDP category receives equal weight to, for example, Canada’s 23 years in the category, Austria’s 35, Italy’s 39, and Spain’s 47.
CheckCell highlights the offending cell in dark red.

Software: Install CheckCell now! (for Microsoft Excel 2010/3, Windows version only) — free for non-commercial use only. The source code for CheckCell can also be downloaded from its GitHub repo.

Paper: A technical paper describing CheckCell’s algorithms,  CheckCell: Data Debugging for Spreadsheets, appeared at OOPSLA 2014.

Video presentation here, with slides.

Press Coverage: NetworkWorld, Phys.Org, i-Programmer, 

We gratefully acknowledge Microsoft Research’s support of this work with a Software Engineering Innovation Foundation Award. This material is based upon work supported by the National Science Foundation under Grant No. CCF-1349784.