Exponential Smoothing Flashcards
Exponential Smoothing Equation
Ft+1 = Ft + α * (Yt - Ft) or Ft+1 = α*Yt + (1-α)Ft
True/False The exponential smoothing method weighs recent observations more heavily than previous ones.
True
True/False Exponential smoothing requires minimum amount of record keeping for past data
True
True/False Exponential smoothing is appropriate where there is a predictable upward or downward trend.
False
True/False In exponential smoothing, a higher value of α gives more weight to recent values.
True
True/False In exponential smoothing, a lower value of α gives more weight to recent values.
False
True/False Exponential smoothing is appropriate where there is no predictable upward or downward trend.
True
Should you use single exponential smoothing or double exponential smoothing when there is a trend in the data?
Double Exponential smoothing
What is another name for Double Exponential Smoothing?
Holt’s Exponential Smoothing
True/False Holt’s Exponential Smoothing is better than Single Exponential Smoothing when there is a trend in the data.
True
True/False Single Exponential Smoothing is better than Holt’s Exponential Smoothing when there is a trend in the data.
False
What is a drawback of Holt’s Exponential Smoothing?
Forecasts may not be good after a few periods
What is β in Holt’s Exponential Smoothing?
A trend factor parameter used to adjust for trend
What are the two equations associated with Holt’s Exponential Smoothing?
Smoothing Level Adjustment
Trend Adjustment
Holt’s Exponential Smoothing
Smoothing Level Adjustment Equation
St = α(Current Value) + (1-α) (Level + Trend Adjustment)(t-1)
Holt’s Exponential Smoothing
Forecast Equation
F(t+m) = St + mTt
How is seasonal data identified?
Seasonal data is identified by finding a persistent pattern that occurs at regular time intervals.
What is the Holt-Winters Model useful for tracking?
Seasonal Patterns
Holt’s Exponential Smoothing
Trend Adjustment
Tt = β (St - S(t-1)) + (1 - β) T(t-1) Tt = β(Change in level in the last period) + (1-β) (Trend Adjustment)(t-1)
Holt-Winters Model
Smoothing Level Adjustment Equation
Holt-Winters Smoothing
Trend Adjustment
Holt-Winters Model
Seasonal Adjustment
Holt-Winters Model
Forecast Equation
True/False
Exponential Smoothing Method is similar to weighted moving average
True
True/False
In Exponential Smoothing one only needs “todays observed” and “yesterdays forecasted value of today” to calculate forecast for tomorrow
True
True/False
A higher value of α gives higher weight to the previous forecast and hence a smoother response to the current observation
False
True/False
There are two equations associated with Double Exponential Smoothing, one with Smoothing Level and one with Seasonality
False
True/False
Double Exponential Smoothing also known as Holt’s Exponential Smoothing it uses a second constant β such that 0 < β < 1 to track trending data better
True