# Chapter 11 Tests

Figure 11.1 presents the results of a static quality check that verifies the internal consistent of each variable and its relationship with other variables in the same dataset. That is, it does not only verify that a variable makes sense in itself (e.g, it is not expected to find negative values for age), but also it checks the consistency of one variable with the others (e.g., It is expected that paid workers receive a positive income, rather than zero or missing income). This flexible tool allows to evaluate the frequency of a given condition, for example, if television==1 & electricity==0.

We used the Stata program qcheck developed by R.Andres Castañeda, Santiago Garriga, and Laura Liliana Moreno (2019). This package is available in Github in the repository worldbank/qcheck.

### References

R.Andres Castañeda, Santiago Garriga, and Laura Liliana Moreno. 2019. “QCHECK: Stata Package for Quality Control of Household Surveys.” Washington, D.C.: World Bank Group. https://github.com/worldbank/qcheck.