Explaining the difference between confidence and credible intervals

Explaining the difference between confidence and credible intervals

🎙 Ben Lambert 👥 148K 📅 May 15, 2018 ⏱ 20 min 👁 23K 📄 tutorial 🧭 2026-08-17
Available in: English (current) Français

Keywords

confidence intervalcredible intervalBayesianfrequentistcoverage probability

Summary

In this video, Ben Lambert explains the difference between confidence intervals (frequentist) and credible intervals (Bayesian) using a medical diagnosis example. The scenario involves a doctor trying to identify a disease (cold, flu, food poisoning, malaria) based on the first symptom (fever, headache, joint pain, nausea). Historical data provides the probability of each first symptom given each disease. The video constructs both types of intervals with at least 80% coverage. For confidence intervals, the parameter (disease) is held fixed and the data (symptom) varies; intervals are built by selecting diseases for each symptom such that, for each disease, the coverage is at least 80%. For credible intervals, the data is conditioned upon and the parameter varies; the table is normalized by row sums to obtain posterior probabilities, and intervals are built to have at least 80% posterior probability. The video compares the two sets of intervals, showing they often overlap but can differ. It also computes the coverage of one type of interval under the other’s perspective, illustrating that confidence intervals guarantee coverage over repeated sampling for a fixed disease, while credible intervals guarantee coverage conditional on the observed symptom. The choice between them depends on the inferential goal and perspective. The video concludes that there is no universally correct interval; it depends on the context and the costs of errors.

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Critical Evaluation

Value of the Information & Strength of the Argument

The video provides a clear and valuable explanation of a conceptually challenging topic. It uses a concrete, intuitive example to illustrate the difference between confidence and credible intervals, which is effective for understanding. The argumentation is solid: the presenter carefully constructs both types of intervals step-by-step, showing the reasoning behind each. He also highlights the key philosophical difference: confidence intervals condition on the parameter and guarantee coverage over repeated sampling, while credible intervals condition on the data and provide a posterior probability. The video also demonstrates that the two intervals can differ and that the choice depends on the inferential goal. The presentation is logical and well-structured, making it a valuable educational resource.

Scientific Rigor, Source Quality, Title Accuracy

The video is scientifically rigorous. The presenter is an academic and the content is based on his textbook ‘A Student’s Guide to Bayesian Statistics’. The example is fictitious but clearly stated as such, and the statistical reasoning is correct. The video does not cite external sources directly, but the description provides links to the author’s website and a lecture playlist. The title accurately reflects the content. The video is well-produced and the explanation is clear. No comments were provided for analysis.

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Title / Content Match

The title accurately reflects the content, which focuses on explaining the conceptual difference between confidence and credible intervals.

Quality & Reliability

8/10

The video provides a clear, rigorous explanation of confidence and credible intervals using a concrete example. The reasoning is logically sound and aligns with standard statistical theory. The presenter is an academic (Ben Lambert, lecturer in econometrics) and the content is based on his textbook. The example is simplified but accurate, and the video is well-structured.

Key Moments

Cited Sources

Concurring Sources

Contribution & Novelties

The video provides a clear pedagogical explanation of the difference between confidence and credible intervals using a simple discrete example. It effectively illustrates the conceptual distinction between frequentist and Bayesian approaches to interval estimation. The video’s contribution is in its clarity and the concrete demonstration of how the two intervals can differ and why. It also highlights the importance of the inferential goal in choosing between them.

Pour aller plus loin :

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Radar Profile

The radar profile shows high scores across all dimensions, indicating a well-balanced and reliable educational video. The quantity and quality of information are strong, and the technical level is appropriate for the target audience. The overall reliability is high, reflecting the academic background of the presenter.

Reliability 8/10