Useful tips for everyday
What does non-normal data mean? Non-normality is a way of life, since no characteristic (height, weight, etc.) will have exactly a normal distribution. One strategy…
How much explained variance is good for PCA? It should not be less than 60%. If the variance explained is 35%, it shows the data…
What are the general chat room rules? Chat Room Rules Rule 1: No spamming. Rule 2: No personal attacks or harassment. Rule 3: Type in…
What does a low silhouette score mean? The silhouette score of 1 means that the clusters are very dense and nicely separated. The score of…
How is seasonally adjusted forecast calculated? The ratio between the actual number and the average determines the seasonal factor for that time period. To calculate…
How do you choose initial centroids in K-means clustering? Specifically, K-means tends to perform better when centroids are seeded in such a way that doesn’t…
Can instrumental variables be correlated? The instrument cannot be correlated with the error term in the explanatory equation, conditionally on the other covariates. In other…
What is the unbiased estimator for variance? In other words, the expected value of the uncorrected sample variance does not equal the population variance σ2,…
What does SD mean in percentile? Standard Deviation Score (SDS) Standard Deviation Score (SDS) Equivalent growth chart percentile 0 (mean or average) 50th +0.67 75th…
Why are there missing data in Bayesian data analysis? Sometimes missing data arise from design, but more often data are missing for reasons that are…