Useful tips for everyday
Which is the best way to bootstrap a statistic? You can bootstrap a single statistic (e.g. a median), or a vector (e.g., regression weights). This…
Why do we use heteroskedasticity robust standard errors? Heteroskedasticity-consistent standard errors are used to allow the fitting of a model that does contain heteroskedastic residuals.…
What are contrasts in linear models? In statistics, particularly in analysis of variance and linear regression, a contrast is a linear combination of variables (parameters…
How are multivariate time series models a problem? Multivariate time-series models involve a large number of unknown parameters, a problem which is greatly exacerbated when…
What does a negative to positive confidence interval mean? The confidence interval (whatever it is) will by definition fall more in the negative side than…
How do you find the probability of a binomial distribution? Binomial probability refers to the probability of exactly x successes on n repeated trials in…
Which is the best k nearest neighbor classifier? The k-nearest neighbor classifier fundamentally relies on a distance metric. The better that metric reflects label similarity,…
Why are the error terms in a regression model correlated? One of the standard assumptions in the regression model is that the error terms εi…
How do you validate clustering result? Dunn index is another internal clustering validation measure which can be computed as follow: For each cluster, compute the…
What is log likelihood in Bayesian network? When evidence is entered in a Bayesian network or Dynamic Bayesian network, the Probability (likelihood) of that evidence,…