Vocabulary.
METRIC
A figure being tracked.
KPI
A metric considered important enough to steer by.
DIMENSION
Something you group by: product, customer, region, period.
SEGMENT
A defined subset of records.
BASELINE
The starting position, before a change.
TREND
Consistent direction across several periods.
VARIATION
Normal fluctuation.
OUTLIER
A value far from the rest.
MEDIAN
The middle value, less affected by extremes than the average.
DISTRIBUTION
How values are spread.
CORRELATION
Two things moving together, which does not establish cause.
SAMPLE
The records analysed, as opposed to everything.
BIAS
Systematic distortion, which more data does not fix.
COHORT
A group defined by when they started.
CHURN
The proportion who stop.
ATTRIBUTION
Deciding which source gets credit.
