Portraits of American religion and irreligion vary and often show wide variation of results due to numerous polling factors such as the commonality of very low response rates for all polls since the 1990s generating unrepresentative sample sizes, biases in wording or topic, polls categorizing people based on limited, shallow or superficial choices to express their complex religious beliefs and practices, and interviewer/respondent fatigue.[11] Since polls routinely fail to predict outcomes of government elections, it casts doubt on the ability of polls to capture accurate portraits of American religion, which is even more complex and personal.[11]