Lecture Notes: Outliers in Data

Question-and-answer flashcards focusing on the concept of outliers in data analysis.

What term describes data points that deviate markedly from the rest of the dataset?

Outliers.

True or False: Outliers must always be removed from a dataset.

False; they may be errors or legitimate observations that require investigation.

Which measure of central tendency is most affected by outliers?

The mean.

What graphical method is commonly used to identify outliers in a distribution?

Box plot (box-and-whisker plot).

Name one technique used to reduce the impact of outliers on analysis.

Winsorizing (capping extreme values).

If an outlier is due to a data entry error, what is the appropriate action before analysis?

Correct the error if possible; otherwise consider removing the observation after documenting the reason.