AC

Why is it considered a good best practice to exclude NULL user_id values from reach and frequency queries?

Because NULL user_id values are deemed invalid traffic in post-impression server-side models.
This would be redundant; records with NULL user_id values have been removed upstream of query processing anyway.
Reach and frequency cannot be accurately determined for NULL user_id values, so this group is excluded to prevent NULL user_id values from skewing the results.

Correct Answer

Reach and frequency cannot be accurately determined for NULL user_id values, so this group is excluded to prevent NULL user_id values from skewing the results.

About the Amazon Marketing Cloud Certification

The Amazon Marketing Cloud Certification covers Amazon's clean-room analytics environment: how AMC data is structured, writing SQL queries against it, and turning results such as overlap and path-to-conversion analysis into audience and media decisions.

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Related Amazon Marketing Cloud questions

  1. 1Why is the AMC sandbox a helpful environment for testing queries?
  2. 2Which action can be used to determine if NULL values are a natural occurrence within your report or the result of aggregation thresholds?
  3. 3user_id values cannot be viewed in the AMC user interface or downloaded from AMC.
  4. 4To minimize the number of values rendered NULL due to aggregation thresholds, you can:
  5. 5How can you determine if NULL values are the result of aggregation thresholds or a natural occurrence within your report?
  6. 6Why is this query unsuitable for assembling a rule-based audience of those who have completed a conversion event? SELECT user_id FROM conversions