Plug a random forest into a causal regression and the confidence interval tightens around the wrong number, because regularisation bias shrinks more slowly than the standard error. Double machine learning fixes this with two devi…
A 700-draw run of the eight-schools model reported R-hat of 1.01 and put the 2.5% quantile of the between-school spread at 0.89, while the exact posterior holds almost 18% of its mass below that value. Calling a sampler takes one…
You add a KL penalty to an RLHF objective, log it, and it prints minus 0.03. KL divergence is provably non-negative, and nothing is broken. One formula does four different jobs in modern machine learning, and almost every confusi…
In the fall of 1960 Rudolf Kalman presented a paper at NASA Ames that engineers found hard to grasp; by early 1961 it was navigating simulated spacecraft around the Moon. The same recursion now computes the exact likelihood of ev…