1. For a detailed treatment of a number of key sales forecasting techniques, the following references are recommended: Albert Battersby, Sales Forecasting (London: Penguin, 1968)
2. Gordon J. Bolt, Market and Sales Forecasting — A Total Approach (London: Kogan Page, 1971), esp. chap. 7
3. John C. Chambers, Satinder K. Mulllik and Donald D. Smith, ‘How to Choose the Right Forecasting Technique’, Harvard Business Review, vol. 49, no. 4 (July–Aug. 1971) pp. 45–74.
4. In this context, care should be taken to distinguish between forecasts which are conditional upon marketing plans, and those which are unconditional — see Harper W. Boyd and William F. Massey, Marketing Management (New York: Harcourt Brace Jovanovich Inc., 1972) pp. 145–6 and chap. 7.
5. In fact, demand forecasts obtained by the exponential smoothing method tend to lag in the context of a strong secular trend, whether upward or downward, and this would explain the poor performance of α = 0.1 in the example. The lag can be adequately compensated for by obtaining an estimate of the trend.