Reading Frequency Curves When Your Broadcast Week Splits Across Two Rating Periods
When a terrestrial campaign in Chungcheong straddles two Nielsen week boundaries, the frequency curve your planner sees depends entirely on which rule you apply to partial-period spots. There is no industry-standard answer — only a consistent one your team agrees on before the post-campaign review.
The split-week problem
Consider a four-week radio flight where week two ends on a Wednesday under the station group's reporting calendar but the rating period resets on Monday. Spots airing Thursday through Sunday of that week could be counted toward either period depending on the export settings in your ad server's weekly rollup.
We encountered this with a regional broadcaster promoting a spring membership drive. Their agency dashboard showed a frequency of 3.2; our reconciled log showed 2.7. Neither number was wrong — they answered different questions.
Our convention
For post-campaign reviews, we assign partial-week spots to the period in which the majority of airing minutes fall. We document the rule in the report appendix so finance and programming can compare year-over-year figures without silent definitional drift.
If your team prefers calendar-week attribution instead, we apply that — but we apply it consistently across all channels in the flight, including digital extensions that use different week definitions.
When to decide
The worst time to choose a partial-period rule is during the final briefing. Decide at scoping, note it in the mid-point checkpoint memo, and no one surprises the general manager with a restated frequency number.