Linked Questions

331 votes
10 answers
199k views

What's the difference between a confidence interval and a credible interval?

Joris and Srikant's exchange here got me wondering (again) if my internal explanations for the difference between confidence intervals and credible intervals were the correct ones. How you would ...
Matt Parker's user avatar
  • 6,127
310 votes
16 answers
115k views

Why does a 95% Confidence Interval (CI) not imply a 95% chance of containing the mean?

It seems that through various related questions here, there is consensus that the "95%" part of what we call a "95% confidence interval" refers to the fact that if we were to exactly replicate our ...
Mike Lawrence's user avatar
110 votes
12 answers
20k views

What, precisely, is a confidence interval?

I know roughly and informally what a confidence interval is. However, I can't seem to wrap my head around one rather important detail: According to Wikipedia: A confidence interval does not ...
dsimcha's user avatar
  • 8,879
51 votes
14 answers
7k views

Clarification on interpreting confidence intervals?

My current understanding of the notion "confidence interval with confidence level $1 - \alpha$" is that if we tried to calculate the confidence interval many times (each time with a fresh sample), it ...
Elliott's user avatar
  • 563
65 votes
11 answers
19k views

Examples of Bayesian and frequentist approach giving different answers

Note: I am aware of philosophical differences between Bayesian and frequentist statistics. For example "what is the probability that the coin on the table is heads" doesn't make sense in ...
41 votes
6 answers
7k views

If a credible interval has a flat prior, is a 95% confidence interval equal to a 95% credible interval?

I'm very new to Bayesian statistics, and this may be a silly question. Nevertheless: Consider a credible interval with a prior that specifies a uniform distribution. For example, from 0 to 1, where 0 ...
pomodoro's user avatar
  • 823
11 votes
7 answers
2k views

Are “Data are fixed” in Bayesian viewpoint and “Data are random” in frequentist viewpoint talking about the same thing mathematically?

In my opinion, in BOTH Bayesian and Frequentist inferences, observational data $x$ are modelled as the observed value of a random variable $X$ which follows a certain probability distribution. ...
Ken T's user avatar
  • 475
25 votes
4 answers
7k views

Weakly informative prior distributions for scale parameters

I have been using log normal distributions as prior distributions for scale parameters (for normal distributions, t distributions etc.) when I have a rough idea about what the scale should be, but ...
John Salvatier's user avatar
24 votes
4 answers
5k views

What is a rigorous, mathematical way to obtain the shortest confidence interval given a confidence level?

After reading the great answer for this question by @Ben, I am a bit confused by the part " set the relative tail sizes as a control variable, and then you find the formula for the length of the ...
Victor Luu's user avatar
13 votes
11 answers
2k views

When is it important for a practitioner to understand CIs?

I have a physician friend who asks me questions about stats. He gets confused about stuff, e.g., the definition of a confidence interval (CI) and its intricacies. For example, he finds the following ...
Yair Daon's user avatar
  • 2,694
14 votes
4 answers
3k views

Is 95% specific to the confidence interval in any way?

I am aware of the misconception that a "95% confidence interval means there is a 95% chance that the true parameter falls in this range," and that the correct interpretation is that if you ...
user5965026's user avatar
12 votes
3 answers
3k views

Do the 2.5th and 97.5th percentile of the theoretical sampling distribution of a statistic always contain the true population parameter?

I am trying to understand the validity of bootstrap percentile confidence intervals and I have stumbled on the following from these slides: Suppose we want to set a 95% confidence interval on $θ$, ...
Antonios Sarikas's user avatar
16 votes
4 answers
4k views

From a Bayesian probability perspective, why doesn't a 95% confidence interval contain the true parameter with 95% probability?

From the Wikipedia page on confidence intervals: ...if confidence intervals are constructed across many separate data analyses of repeated (and possibly different) experiments, the proportion of ...
Rasmus Bååth's user avatar
8 votes
5 answers
1k views

why regularization is slower slope and not higher?

I am reading about regularization in Aurelien Geron's book. I do understand that given a model $\beta_0$+ $x$ $\beta_1$ , regularization means: If we allow the algorithm to modify $\beta_1$ but we ...
Chicago1988's user avatar
12 votes
3 answers
7k views

What does a confidence interval (vs. a credible interval) actually express? [duplicate]

Possible Duplicate: What, precisely, is a confidence interval? Yes, similar questions have been asked before, but many of the answers seem contradictory and don't address my issue. (Or my ...
henle's user avatar
  • 221

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