5.1 Administration mode
An important feature for selecting items in an instrument is the planned administration mode for the test. Some items are especially developed to observe directly, whereas others are developed to be reported by a caregiver.
An instrument with directly observed items, often also requires additional material. For example an milestone about stacking two blocks, requires two actual blocks so that the child can demonstrate this.
Caregiver reported items need to be clear enough. Since the items to measure the D-score all originate from previously validated instruments, most of these checks have already been done.