Ground-truthing and contextualizing data

While analyzing ACS data, it’s important to review your data and findings in context. This means looking into other related datasets, qualitative information, and ground-truthing data with community. It’s important to make sense of ACS data in concert with other sources of information – specifically, information directly from the groups you are measuring in the Census.

Ground-truthing data means reviewing findings with direct community input, specifically the community that is supposed to be reflected in the data. Read more about centering community during data analysis in this guide to GIS for Equity and Social Justice (applicable to other non-GIS analyses as well!).

You can also contextualize analysis findings by reaching out to experts in a field to verify or comment on the data. This could involve reaching out to CBOs or other advocacy group from the community or population group being analyzed or other academic experts.

📌Ground-truthing data in the past has resulted in important changes to analyses for more thoughtful and accurate findings. As one example, when working on one project measuring the San Francisco population by race/ethnicity, the SF Native American population was first measured using the Non-Hispanic “American Indian and Alaska Native alone” category on this B03002 table. However, when reviewing these population numbers with Native American community groups and leaders, these numbers were not representative of the real population size in SF. In addition to potential undercounting, so many people who identify as Native American also identify with other race/ethnicity categories so are included in “Two or more” categories. A much better table was agreed upon – the B02010 table that counts anyone who identified as American Indian or Alaska Native (alone or in combination with any other races). This update resulted in a very different total number – and increased accuracy as validated by community leaders.