# Guide

### Glossary

#### Sorting Subreddits

**Activity**: Subreddits with the highest level of activity are ranked higher.**Relevance**: Subreddits that are most relevant to the keyword are ranked higher.**Popular**: Subreddits with the most subscribers will be ranked higher.

#### Sorting Reddit postings

**New**: Posts that have been created most recently are ranked higher.**Hot**: Posts that have received the most upvotes and comments in the last 24 hours are ranked higher.**Rising**: Posts that have received the most upvotes in the last hour are ranked higher.**Top**: Posts that have received the most upvotes ever are ranked higher.**Controversial**: Posts that have received the most downvotes are ranked higher.

#### Mean

The mean, also known as the average, is the sum of all the values in a set divided by the number of values in the set. It is a measure of the central tendency of a set of data.

#### Standard Deviation

The standard deviation `SD`

is a measure of how spread out a set of data is. It tells you how far each data point is from the mean, on average. A high standard deviation means that the data points are more spread out, while a low standard deviation means that the data points are closer together.

#### Median

The median `M`

is the middle number in a set of numbers when they are arranged in order from smallest to largest. If you have an even number of numbers in your set, the median is the average of the two middle numbers.

#### Weighted mean

A weighted mean is an average that takes into account the importance of each data point. It is calculated by multiplying each data point by a weight, then adding the products and dividing by the sum of the weights.

Weighted averages are often used in situations where some data points are more important than others.

#### Weighted standard deviation

Weighted standard deviation is a measure of how spread out a set of data is, taking into account the importance of each data point. It is calculated by multiplying each data point by a weight, then calculating the standard deviation of the weighted data points.

The weighted standard deviation is often used in situations where some data points are more important than others.

#### Weighted median

A weighted median is a median that takes into account the importance of each data point. It is calculated by multiplying each data point by a weight and then finding the median of the weighted data points.

Weighted medians are often used in situations where some data points are more important than others.