Useful tips for everyday
What is the condition number of an identity matrix? The condition number of the matrix measures the ratio of the maximum relative stretching to the…
What is the logic behind ANOVA? The logic of ANOVA is very much like the logic of a t test; we might be able to…
What is Cochrane Orcutt procedure? Cochrane–Orcutt estimation is a procedure in econometrics, which adjusts a linear model for serial correlation in the error term. Developed…
How do you improve a box plot? A possible approach is to thicken appropriate vertical lines in the box. Thus, if a distribution is right…
What is IRT type? The item response theory (IRT), also known as the latent response theory refers to a family of mathematical models that attempt…
How to calculate a confidence interval in logistic regression? The usual way is to compute a confidence interval on the scale of the linear predictor,…
When do you use categorical data in Excel? When using categorical data, you usually convert those to either number labels (one additional column with one…
Which method is suitable for data reduction? One of the methods used for data reduction is sampling as it is capable to reduce the large…
How do you calculate unconditional variance? In finance, risk is usually approximated using the second moment (ie the variance). Similarly that for the mean process,…
How does step AIC work in R? The stepAIC() function performs backward model selection by starting from a “maximal” model, which is then trimmed down.…