The socket for wood floors has a small flange at the top of the socket with screw holes to help stabilize the installation in the wood floor.
Some customers use an industrial grade epoxy or a hydraulic cement to fix the sockets in the ground. The materials used really depends on what your installer feels comfortable using with your floor.
When the sockets are installed, the installer must ensure that the socket is completely level. If it is not level, your posts will look all crooked when installed. If the socket is tilted, even by what seems a little bit, the post will look drastically tilted. We would recommend testing the position of the sockets by putting the post into the socket before it is installed to ensure that it is level and then remove the post to finish the installation. Removing debris from the socket will also help with a clean, level installation as well.