Linked Questions

17
votes
7answers
18k views

Difference between Anomaly and Outlier

What is the difference between Outlier and Anomaly in the context of machine learning. My understanding is that both of them refer to the same thing.
1
vote
5answers
8k views

How can I identify and remove outliers in R

I am performing regression analysis on prices of product that we have purchased, based on size and other attributes. However there are often buys in odd circumstances which factor into the price, ...
2
votes
2answers
7k views

Dealing with outliers in dependent variables?

Here is the boxplot of whole data: The data is about predicting the number of visitors (Locals, Foreigners, Total visitors, i.e Locals + Foreigners) in national park given certain parameters like ...
2
votes
1answer
3k views

Outlier detection for skewed data

I have a dataset as below: 4.8856 4.8914 4.9125 4.9338 4.9563 4.993 4.9947 4.9947 4.995 5.2932 4.981 4.981 4.981 4.982 4.982 4.982 4.982 4.983 4.983 4.984 4.984 ...
1
vote
1answer
4k views

Transforming positively skewed data with positive and negative values

My data (see image below) is positively skewed and contains both positive and negative values. I'd like to transform it to achieve normality so I can apply a repeated measures ANOVA, but can't find a ...
4
votes
1answer
2k views

Popular methods for outlier detection (right skewed distribution)

What are the popular methods for outlier detection in univariate data, which do not assume normal distribution?
0
votes
1answer
2k views

Finding outlier values for non-normally distributed data

I have univariate data (38 is the sample size).The distribution is certainly not normal. How can I find the outliers? I used z-score but am not getting a desired result.
2
votes
1answer
282 views

How to predict when an outlier is going to occur if it's shown to occur repeatedly?

I know my title seems to go against what an outlier is, but I don't know any other way of phrasing it. Let's say I have a spreadsheet, and a column with the following values: [From newest-to-oldest] ...
0
votes
0answers
135 views

When removing outlier is right? Removing techniques for outliers in R [duplicate]

I was searching outlier removal in R and I saw some comments related to almost never you should remove outlier from dataset. I wonder when we should remove outlier? I have a dataset consisting ...
0
votes
0answers
131 views

Does the “IQR outlier removal method” removes all outliers?

There is a dataset I'm working on and there are 6 columns with continuous values which are noisy. Here is how these columns look like in term of histogram and boxplot: As you can see, these columns ...
0
votes
0answers
22 views

Is it good practice to use a Box-Cox transformation on non-normal data to remove outliers through z-scores? [closed]

One of the approaches statisticians use to remove outliers in normal data is to calculate z-scores and remove any observations that are beyond +3 and -3 standard deviations. My questions are: Is this ...