At mySidewalk, we strive to provide a comprehensive data library for your community. However, it’s not always possible to deliver data for every topic, time, or geography. When data isn’t available, you may see “NULL” or “No Data” in our products.
Common Questions
1. Why does some data appear as “No Data” or “NULL” in mySidewalk?
This happens when we cannot generate data values for specific combinations of geography, topic, and time due to limitations in raw data or other factors.
2. Why is this data available for other cities but not my city?
Data availability depends on the granularity and scope of the raw data sources. If data is not published for your city, we cannot generate it.
3. Why is data available for Census Tracts but not neighborhoods?
Some raw data sources do not provide the level of detail needed to calculate values for smaller geographies.
4. Why does it say “No Data” when Seek availability shows 100%?
Seek availability is rounded to display whole numbers. For example, 99.5% availability may appear as 100%.
Key Factors Affecting Data Availability
Data availability depends on three key factors:
Geography: Your area of interest, such as ZIP code, city, or state. With over 450,000 geographies, data availability varies widely.
Topic: The specific data or dataset you’re exploring.
Time: The period for which data is requested. The default is the most recent available data.
Note: Selecting a combination of these three factors determines data availability. Some combinations may result in “NULL” or “No Data.”
Reasons for “NULL” or “No Data”
Here are common reasons why data may not be available:
Raw Published Data Lacked Granularity
Some data sources publish information at broader geographic levels only (e.g., state or county).
Example: CDC data may only be available at the county level and not at the block group level.
Raw Data Suppressed for Privacy or Sample Size
Data may be withheld if sample sizes are too small or if publishing the data could risk individual privacy.
Example: Placeholder values for small counties in Ohio result in “NULL” or “No Data.”
Raw Published Data Already Calculated or Manipulated
Some data is published as ratios or percentiles, preventing further calculations for additional geographies.
Example: County-level death rates from CDC data cannot be recalculated for Census Tracts.
Data Calculated Using Apportionment
Apportionment is used to estimate data for non-Census geographies like neighborhoods. If insufficient data points exist, the result is “NULL.”
Example: A city council district with zero captured block points cannot have calculated data.
Failed QA Testing
Data that fails quality assurance checks is excluded to ensure reliability.
Example: Data with excessively high margins of error or unverifiable outliers.