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Next time try mergic! It's pretty cool for these sorts of messy, real-world string matching tasks: https://github.com/ajschumacher/mergic


Zach: I went to a talk about mergic recently. How does it deal with merging columns other than the match key?

The larger issue is whether this is a problem of tools. Ideally, if there is a tool, I'd like it to solve the problem completely. Tools like mergic solve part of the problem; then, the analyst must review the output to solve the rest of it. The time invested in learning the new tool often doesn't pay off.

But I'm being too demanding I think. The underlying issue is incomplete information. There isn't a clear cut answer to whether Scott in "Scott Lewis" is a first or last name. There is no hope that a tool can give a sure answer. So tool developers give probabilities. Then people have to interpret those probabilities and make decisions.

The other challenge is the issues are not known in advance. Solutions often solve one problem while exacerbating a different problem.


Mergic only creates the match key. After joining the match key to each of the parent tables, you do the join as you normally would. This means you can run mergic on multiple pairs of columns between the 2 tables, join each match key to both tables, and then merge the 2 tables on multiple keys in the final step.

What I personally like about mergic is it explicitly includes a "human makes edits step." So the algorithm does 80% of the work (grabbing all the easy cases) and you can focus your manual work on the 20% cases like "Scott Lewis" vs "Lewis Scott."


Here's an excellent mergic tutorial:


Kaiser - welcome to the big bad world of data quality. Where people think computers can perform magic! Did you consider the "Jr. or III" as well? No tool can handle bad data. This is one of many reasons why, for all the hype about "big data", it's small data that matters. If the developers had used a RDBMS with constraints, had determined how to identify people (email address in both places, etc)..

Also, a lot of older folks share an email account (usually the one their ISP sets up for them). So even email can't be relied upon to reach a single person.

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