How to be a Data Detective

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When the Louisiana Department of Education released data showing a significant spike in high school performance rates, Mercedes Schneider, a public school teacher in St. Tammany Parish with a PhD in applied statistics, had an inkling that something was fishy. Schneider noticed that the jumps were so large as to be statistically improbable.

While it helps to have a background in statistics, Schneider insists that anyone can be a data detective—it’s all a matter of knowing where to look.  “Corporate reform is not about what works. If it were, there would be no data distortion, nor data hiding, nor data removal,” says Schneider. In this post, Mercedes Schneider provides six steps that will help you to locate data.    

Step 1: Download, download, download

Data quality is everything. If at all possible, permanently download data files the moment they are released. Reformers like to change and remove data as it suits them. They also like to make data disappear.

Step 2: Learn to cross check

(Cross checking isn’t difficult—it just means comparing the numbers in one data set to the numbers in another.) Compare the data sent to public officials with the data set made available to the public. Also, compare data available on local school system websites to state data, or data available on the US Department of Education website to state data. Discrepancies will highlight what reformers are attempting to hide, sometimes in plain sight. (One sneaky trick to look out for: when officials rename a column of data in order to conceal what it really is).

Step 3: Compare and contrast

Compare released data to the publicized DOE bulletins about how scores are to be calculated. Look for missing steps. Publicize such findings.

Step 4: Beware of percentages

Beware of data reported only as percentages. If necessary, file a FOIA (Freedom of Information Act) request for actual numbers.

Step 5: Go on the hunt for missing data

If you suspect that data is being hidden, look at individual school district websites for missing data. Although many might simply link into their DOE website, some actually have saved their own files and are not dependent upon DOE links. Cross check local files with what the DOE might be offering to the public.

Step 6: Ask for help

If you need help untangling a data mystery, ask an expert for help. “You can ask someone like me for an explanation,” says Schneider.


Mercedes Schneider blogs at Contact her at