Q: Why don't you put the time taken to compress?
A: There is no accurate way to measure it. It is influenced by too many factors. That,
and i often use the computer while the programs are compressing in the background.
This greatly effects the time, because i am using the CPU for other tasks.
Q: Why do you test data which is already compressed such as MP3 and PNG?
A: To really test the compression programs out. Some programs actually generate
significantly larger archives than the original data. Both are highly optimised
and compressing them reveals which programs are REALLY good at compressing stuff.
Q: Program x just updated to version y. Why don't you test the new version?
A: Usually, new versions fix bugs or add new features. But the compression remains unchanged.
A good example is WinHKI. Updates often, compression is the same. If i am not updating a
program, it's probably for this reason.