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- 1$\begingroup$ So you don't advocate cross-validation through splitting of large data-sets for predictive model testing / validation? $\endgroup$OFish– OFish2014-12-15 03:42:01 +00:00Commented Dec 15, 2014 at 3:42
- 12$\begingroup$ No, unless the dataset is huge or the signal:noise ratio is high. Cross-validation is not as precise as the bootstrap in my experience, and it does not use the whole sample size. In many cases you have to repeat cross-validation 50-100 times to achieve adequate precision. But in your datasets have > 20,000 subjects, simple approaches such as split-sample validation are often OK. $\endgroup$Frank Harrell– Frank Harrell2014-12-15 04:17:39 +00:00Commented Dec 15, 2014 at 4:17
- 2$\begingroup$ That's really good to know! Thanks. And coming from you, that's a great "source" of info. Cheers! $\endgroup$OFish– OFish2014-12-15 04:43:50 +00:00Commented Dec 15, 2014 at 4:43
- 3$\begingroup$ Split-sample validation often performs worse than rigorous bootstrapping. Create an outer bootstrap look that repeats all supervised learning steps (all steps that use Y). The Efron-Gong optimism bootstrap estimates how much the predictive model falls apart in data not seen by the algorithm, without holding back data. $\endgroup$Frank Harrell– Frank Harrell2018-12-05 00:06:47 +00:00Commented Dec 5, 2018 at 0:06
- 2$\begingroup$ Yes with emphasis on repeating. It's the single split that is problematic. $\endgroup$Frank Harrell– Frank Harrell2019-05-28 17:56:47 +00:00Commented May 28, 2019 at 17:56
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