Photograph: bird's eye view of a site; interview: personal analysis and biased; tax records: limited accessibility; biography: unreliability of human memory.
Explanation:
There are generally always some drawbacks when considering different sources of historical information and a good researcher has to take these factors into account. Photographs are limited because they give you very little context. Interviews can be limiting because you get a personal view from just one individual. Tax records are likely protected due to privacy concerns and statutes. Biography can have drawbacks as well because the person may embellish past events or overemphasize the significance or attribute meaning in ways that are not entirely truthful or objective.
