**Daily update | 27 February, 2022**

# StackExchange

#### How do I calculate $\sigma^2$ within the $\varepsilon = N(0, \sigma^2)$ notation

**Source:** stats**Views:** 51**Score:** 3**Tags:** normal-distribution variance residuals error autoregressive

#### Multiplicity correction after performing non-parametric tests

**Source:** stats**Views:** 12**Score:** 3**Tags:** nonparametric multiple-comparisons wilcoxon-mann-whitney-test

#### Compare Books using book categories list NLP

**Source:** datascience**Views:** 8**Score:** 2**Tags:** machine-learning python nlp nltk spacy

#### Purpose of validation set in model.fit?

**Source:** stats**Views:** 11**Score:** 1**Tags:** time-series validation

#### When to Normalize Training Data

**Source:** stats**Views:** 10**Score:** 1**Tags:** machine-learning normalization feature-engineering