ENTRIES TAGGED "anomaly detection"

New approaches to anomaly detection

A practical example of how anomaly detection makes complex data problems easier to solve.

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As new tools for distributed storage and analysis of big data are becoming more stable and widely known, there is a growing need for discovering best practices for analytics at this scale. One of the areas of widespread interest that crosses many verticals is anomaly detection.

At its best, anomaly detection is used to find unusual, rarely occurring events or data for which little is known in advance. Examples include changes in sensor data reported for a variety of parameters, suspicious behavior on secure websites, or unexpected changes in web traffic. In some cases, the data patterns being examined are simple and regular and, thus, fairly easy to model.

Anomaly detection approaches start with some essential but sometimes overlooked ideas about anomalies:

  • Anomalies are defined not by their own characteristics but in contrast to what is normal.

Thus …

  • Before you can spot an anomaly, you first have to figure out what “normal” actually is.

This need to first discover what is considered “normal” may seem obvious, but it is not always obvious how to do it, especially in situations with complicated patterns of behavior. Best results are achieved when you use statistical methods to build an adaptive model of events in the system you are analyzing as a first step toward discovering anomalous behavior. Read more…

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