Lecture Suggestions – Chapter 3
Example 1: Moving Average
2. Use the spinner button (upper left hand corner of the template) to set the number of periods used in
3. Now set Periods=2 and demonstrate that each forecast is the average of the previous 2 actual data
points by using the spinner button below the graph to set the period and using the cursor to point to
the forecast and the actual data points on the graph.
4. Set Periods=3 and demonstrate (again using spinner button below the graph and using the cursor to
point on the graph) that each forecast is the average of the previous 3 actual data points.
5. Finally, use the spinner button to step back to Periods=2 and then back to Periods=1, showing that
Example 3: Exponential Smoothing
1. Select the Example 3 worksheet, note that data has been entered for periods 1-11.
2. Set the smoothing constant a=0 (you may either enter zero or use the spinner button beside a) . This
results in using the first forecast for all forecasts, i.e. “complete” smoothing.
3. Now go to the other extreme and set a=1. This results in using the previous actual data point for the
4. Then set a=.5, this results in a forecast that is halfway between the previous forecast and the previous
5. Now use the spinner button to step between a=0 and a=1 (the increment Da should be .1). Point
6. Finally, you may optimize a by looking for the value of a that will minimize MAD.
a. With Da=.1, repeatedly press the spinner button and you will see that MAD is minimized
somewhere between a=.6 and a=.8.
1. Select the Example 1 worksheet, note that data has been entered for periods 1-6. You may want to