Limitations and Use of Data

During the year, we produce preliminary estimates broken down by sampling wave, mode of fishing, and state. These estimates – particularly at lower levels of aggregation – may be imprecise due to small sample sizes. All preliminary estimates will likely be revised before being posted as final. The direction and magnitude of such revisions are unpredictable.

For these reasons, MRIP estimates are best viewed in aggregate - annually and at the state or regional level.

Here are a few additional considerations to keep in mind as you review MRIP data:

• The percent standard error, or PSE, is a measure of precision presented with all estimates. Estimates should be viewed with increasing caution as PSEs increase beyond 25.  Large PSEs – those above 50 – indicate high variability around the estimate and therefore low precision. Estimates with large PSEs should be viewed cautiously.
• When comparing catch estimates across an extended time series, note differences in sampling coverage through the years. Some estimates may not be comparable over long time series.
• Weight estimates are minimums and may not reflect the actual total weight landed or harvested.  Tabular output provides the number of fish that are not represented by the weight estimate.

Please review the glossary for other important tips on using MRIP data.