Constraints and Assertions

Posted on Thu 26 November 2015 in TDDA • Tagged with tdda, components

Consistency Checking of Inputs, Outputs and Intermediates

While the idea of regression testing comes straight from test-driven development, the next idea we want to discuss is associated more with general defensive progamming than TDD. The idea is consistency checking, i.e. verifying that what might otherwise be implicit assumptions are …

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How is this Misleading Data Misleading Me?

Posted on Fri 13 November 2015 in TDDA • Tagged with tdda, implementation, interpretation, correctness

"Why is this lying bastard lying to me?"

Louis Heren,1 often attributed to Jeremy Paxman.

In a previous post, we made a distinction between two kinds of errors—implementation errors and errors of interpretation. I want to amplify that today, focusing specifically on interpretation.

The most important question to …

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Why Test-Driven Data Analysis?

Posted on Thu 05 November 2015 in TDDA • Tagged with questions, tdda, tdd

OK, everything you need to know about TeX has been explained—unless you happen to be fallible. If you don't plan to make any errors, don't bother to read this chapter.

— The TeXbook, Chapter 27, Recovery from Errors. Donald E. Knuth.1

The concept of test-driven data analysis seeks to …

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