Because "this" as the second argument to the ko.dependentObservable doesn't refer to the viewModel object (it's still being declared), it refers to whatever the

Because "this" as the second argument to the ko.dependentObservable doesn't refer to the viewModel object (it's still being declared), it refers to whatever the current context is. To check it, console.log or alert "this" inside the function and see what it's value is.