In stock assessment, what does a confidence interval convey?

• A. The exact true value of the metric.
• B. A range within which the true value lies with a stated probability.
• C. The maximum allowed error.
• D. The number of data points collected.

Answer: (B)

In stock assessment, a confidence interval communicates how uncertain our estimate is by giving a plausible range for the true value and attaching a probability to that range. For example, a 95% interval means that if we could repeat the assessment many times under the same conditions, about 95% of the intervals would contain the real value (like true biomass or true fishing mortality). It doesn’t promise the exact value for the current study—uncertainty comes from sampling, measurement error, and model assumptions. The interval widens when data are noisy or the model is less certain and narrows when data are precise and the model fits well. This is why the interpretation is a probability-based range, not an exact value, a maximum error, or simply the number of data points collected.