This question has arisen on the photography forum of a wildlife site which I regularly use. A member asked about the best methods and sizes for uploading images to that site and in my reply I mentioned that I now use BiCubic Interpolation (or better if available) for substantial downward resizing.
I am talking about starting with say in excess of 3000 x 2000 pixels and ending up with 800 x 500 or thereabouts.
Somebody has questioned this method and repeated the theory of BiCubic for increasing size but BiLinear for reducing.
Now I know that was recommended when I was learning digital editing about 8 years ago but I have read that with today's massive image starting sizes it is better to use BiCubic for reduction as you are discarding a lot of pixels on the way down.
Also, I often do the resize in 2 stages, which was the old idea; but is this still relevant? I remember reading, some time ago, that you should never alter your image size by more that 50% in one go.
So what do other people do?