In a KE-chain task form, it is not yet possible to give permissions on field editing. That means that the properties configured as 'view' cannot be edited by managers nor members assigned, while the properties configured as 'edit' can be edited by both classes of users. This might pose a problem when you, as a manager, would like to review the work performed by the member you assigned, but you would prefer to be the only one that can edit the respective 'verification' fields.
Fortunately, due to the flexibility of KE-chain, you can do that through a second, almost identical, task form.
Let's say you have assigned task called 'Design front spokes' to a user. The user needs to calculate the optimum number of spokes of a bicycle front wheel and the distance between them. He performs his calculations and writes in the results. He marks the task as 'Complete':
However, unbeknownst to the user, there is a second task called 'Design front spokes - verification' in the work breakdown tree. That task is assigned to you and you only, as you are the project manager. That means you are the only one that can access it or even know of its existence.
Finally, the fact the user marked his task as 'Complete' signals you that you can verify his results. Your task has been configured almost the same as his, for two exceptions:
all the properties in his task are only 'viewable' for you
you have two more properties set as 'edit'
You can use the properties to write your findings about the results and approve or not approve them. Alternatively, you user can have the verification properties configured in his task in order to see your resolution as soon as possible and act accordingly. Also, you can unlock the properties in the verification task and redo the calculation by yourself. The possibilities are endless!