I am currently following a tutorial “Houdini isn't scary” which is about replacing a scatter node with a DOP system via a switch node. The problem is that the “attribute transfer” node does not transfer the normals of the geometry to the DOP system. i have actually followed the steps in the tutorial exactly.

One thing to check is if the normals to be transferred are on the vertices rather than the points. Otherwise, posting your hip file would help.

okay, thank you, the hip file is attached in the question. here it is again:

Sorry, hadn't noticed the file.

So first you're deleting the whole geometry on the left branch, so there's nothing to copy normals from. I disabled the Delete sop.

Then, in your Normals sop, add you normals to your points insted of your vertices.

Finally, you have to actually specify the attribute you want to transfer in your Attribute Transfer node, so enter N in the points list.

Should work.