The quantities can be given in technical terms, like GW for power capacities, or in numbers of items. Qualitative measuring mostly uses the sales turnover as an indicator. That means that the market price and the quantity are taken into account. Besides the market volume, the market potential is of equal importance. It defines the upper limit of the total demand and takes potential clients into consideration. Although the market potential is rather fictitious, it offers good values of orientation. The relation of market volume to market potential provides information about the chances of market growth. The following are examples of information sources for determining market size: Government data Trade association data Financial data from major players Customer surveys Market trends Market trends are the upward or downward movement of a market, during a period of time. The market size is more difficult to estimate if one is starting with something completely new. In this case, you will have to derive the figures from the number of potential customers, or customer segments. Besides information about the target market, one also needs information about one's competitors, customers, products, etc. Lastly, you need to measure marketing effectiveness. A few techniques are: Customer analysis Choice modelling Competitor analysis Risk analysis Product research Advertising the research Marketing mix modeling Simulated Test Marketing[5] Changes in the market are important because they often are the source of new opportunities and threats. Moreover, they have the potential to dramatically affect the market size. Examples include changes in economic, social, regulatory, legal, and political conditions and in available technology, price sensitivity, demand for variety, and level of emphasis on service and support. Market opportunity A market opportunity product or a service, based on either one technology or several, fulfills the need(s) of a (preferably increasing) market better than the competition and better than substitution-technologies within the given environmental frame (e.g. society, politics, legislation, etc.). Applications The literature defines several areas in which market analysis is important. These include: sales forecasting, market research, and marketing strategy. Not all managers will need to conduct a market analysis. Nevertheless, it would be important for managers that use market analysis data to know how analysts derive their conclusions and what techniques they use to do so. References George J. Kress,Taryn Webb, and John Snyder, Forecasting and Market Analysis Techniques: A Practical Approach (Westport, CT: Quorum Books, 1994) See also Market research Marketing