Correlation as measure of similarity

1. Is correlation a similarity measure?
2. Is correlation same as similarity?
3. Is Pearson correlation a similarity measure?
4. How do you measure similarity?

Is correlation a similarity measure?

Contrary to your statement, correlation does not measure similarity if similarity means that the highest value of a measure is achieved if and only if all values are identical. (Any one can reverse the game and define a measure and then give it some name from their language as a label.

Is correlation same as similarity?

Correlation is the cosine similarity between centered versions of x and y, again bounded between -1 and 1. People usually talk about cosine similarity in terms of vector angles, but it can be loosely thought of as a correlation, if you think of the vectors as paired samples.

Is Pearson correlation a similarity measure?

Pearson Correlation Coefficient (PCC) is one of the most popular similarity measures for Collaborative filtering recommender system, to evaluate how much two users are correlated. While Correlation-based prediction schemes were shown to perform well, they suffer from some limitations.

How do you measure similarity?

To calculate the similarity between two examples, you need to combine all the feature data for those two examples into a single numeric value. For instance, consider a shoe data set with only one feature: shoe size. You can quantify how similar two shoes are by calculating the difference between their sizes.