To add, it's called "connascence", meaning litterally "born together". Between elements A and B, connascence is the property by which there is at least one change to A that would necessitate a change in B in order to preserve overall corectness. Great discussion of this in Meillir Page-Jones book What Every Programmer Should Know About Object Oriented Design.


>> If the middle tier is to really isolate the front end from the back end we should be able to change the field names on the backend without needing any changes to the front end. If we are using properties in the middle tier that correspond to the back end field names and the front end is binding to those properties then making a change on the back end requires changes also to both otehr tiers.