Solved – what is the difference between Bayesian optimization and kriging

bayesian optimizationgaussian processkriging

Both methods use Gaussian process, and kriging uses the Best Linear Unbiased Predictor (BLUP) to predict the mean (this is not seen in Bayesian optimization?). At the bottom line, they also have covariance matrix, whose inverse has to be computed before moving out to the next sample point. As far as I understand,

  • Bayesian optimization yields a posterior pdf with mean and variance
  • kriging yields a predicted mean and MSE $\sigma^2$

Obviously they are different for some reasons. Why are they different?

Best Answer

I believe you mean Gaussian processes rather than Bayesian optimisation. Bayesian optimisation is the use of Gaussian processes for global optimisation. Essentially you use the mean and variance of your posterior Gaussian process to balance the exploration and exploitation trade off in global optimisation (i.e. You want to fin the highest local point but you don't want to fall into local extrema).

Gaussian processes have been around since the 60s as far as I'm aware and maybe even earlier than that. As such they have been used and modified in different fields. In geostatistics, which at one stage was dominated by the French research community, they became 'kriging' and many scaling approximations and kernels were derived specifically for geo-spatial low dimensional data.

In statistics and later machine learning they remained being referred to as Gaussian processes. Unfortunately this occasionally lead to people reinventing the wheel when it came to approximate approaches and theoretical analysis.

Now it's not uncommon that people use the terms interchangeably. For example Tom Nickson created a kronecker product sparse variation along approach Gaussian Processes which he called Blitz-Kriging.

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