I have installed the requirements:
- GDAL Complete 1.11 framework package
- Matplotlib Python module
and I've made sure these requirements are properly installed by checking library/frameworks and /Library/Python/2.7/site-packages.
When I go to install QGis I get an error message stating "The installation has failed. The installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance."
I am running El Capitan 10.11.