Lesson 2: Pipeline Essentials Flashcards
What is the difference between time series data and transactional data?
Time series data are equally spaced with respect to an index, transactional data are not.
What is noise in the data?
Noise is a pattern in the data that is not systematic and therefore not replicable
What is a white noise series?
A white noise series is a series of independently, identically distributed random variables
(a time series consisting only of noise)
What is autocorrelation?
a measure of association between successive values of a time series
Series values immediately preceding current values
What is the correlation between the current value and the first lag called?
first-order autocorrelation
What are signs a series contains autocorrelation?
What does the signal part of the irregular component of the series consist of?
autocorrelation
What is level in a time series?
the nonzero value of the series at a particular point in time
What is a trend in a time series?
Trend is the long-term pattern of the mean of the series
What is seasonality in a time series?
predictable deviations of the series patterns from the trend component
What is the difference between seasonality and cycle in a time series?
Seasonality refers to a regular, repeating cycle, whereas cycle is more general
What are exogenous effects are also referred to as?
explanatory effects
What is an exogenous effect?
The effect of other series, external to the one of interest, is often referred to as an exogenous effect.