<p>It's interesting. I find a post like this one <a href="https://stats.stackexchange.com/questions/146598/confidence-measures-for-gaussian-mixture-models">Confidence measures for Gaussian mixture models</a> to be an appropriate use of the word confidence, in the sense that they are interested in reporting the uncertainty around a number of predicted clusters using a mixture model, but an <em>interval</em> is not an appropriate reporting tool.</p>

<p>I think the vast majority of these posts can be classified under either "confidence interval" or "hypothesis testing". I think posts such as the above could be classified as uncertainty. Conversely, perhaps no tag is necessary in that case. Any statistical practice should have an associated method to measure uncertainty... that's basically what we do as statisticians.</p>
