Exploratory Analysis

• Data Summarization

• Different Databases

  • Operational database
    Transcations OLTP (online transactions processing)
  • Datawarehouse (for business applications) Aggregate queries OLAP (online analytic processing)

• Visualization

Summary Statistics

Percentiles

Mean

Trimmed mean

Having an estimate on the fraction of outliers $p $ in data

If $p=100 \%$, then the result is Median.

Variance

Absolute average deviation (AAD)

More rboust than variance

Median absolute deviation

Correlation coefficient