A marker is something that makes up for the delay of reinforcement by signalling to the subject "reinforcement is coming" For example saying "good dog" before giving your dog a treat. Secondary reinforcement is when something becomes reinforcing / causes pleasure through it's association with a reinforcement. e.g. dog loves to love praise. People love money because you can buy stuff with money. So aren't they the same thing? Are there any concrete experiments or exampes of where they are different? If you go here http://books.google.com.tr/books?id...sychology marking procedure lieberman&f=false On page 332 it says that because they used the marker whether there was reinforcement or not, they can be confident it wasn't a secondary reinforcer. I don't understand how that follows.