Sample Size and Statistical Theory

Sample Size and Statistical Theory


A practical question in much of marketing research involves the determination of sample size. A survey cannot be planned or implemented without knowing the sample size. Further, the sample-size decision is related directly to research cost and therefore must be justified.
In the previous chapter, several practical approaches to obtaining sample size were presented. These approaches are extremely sensible, will lead to reasonable sample-size decisions, and in fact are used often in marketing research. There is, however, a formal approach to determining sample size using statistical theory. It is useful to understand this formal approach— the subject of this chapter—for several reasons. First, in some contexts it can be applied directly to make more precise sample-size decisions. Second, it can provide worthwhile guidance even when it may not be easy to apply the statistical theory. Finally, the discussion serves to introduce some important concepts and terms of sampling that, together, will generate a deeper understanding of the process. Among these terms and concepts are population characteristics, sample characteristics, sample reliability, and interval estimation. Each of them will be introduced, and then the sample-size question will be considered.

Comments

Post a Comment

Popular posts from this blog

Office of International Trade

Office of International Trade The Office of International Trade offers many programs for exporters, such as: • Export Counseling: Through Export Counseling, individual counseling by international trade specialists is offered when available in the area. For this purpose it might be wise to investigate the counseling staff that is available from both the US&FCS and SBA if both offices are equally available to you. • Export Training: Export Training is generally offered by means of co-sponsorship with DOC and/or private sector organizations. • Legal Assistance: The Export Legal Assistance (ELAN) program offers free, initial consultations on the legal aspects of exporting through an arrangement with the Federal Bar Association by qualified attorneys in the International Law Council. • Export Information Program (XIS): The XIS provides data that is based on SITC product categories taken from U.N. data. Check for submission dateon this and, for that matter, all other sources of inf...
Read more

Opportunity bank

Opportunity bank The opportunity bank is a computerized database maintained by OPIC to match American investors with developing country projects. It currently has more than 1,000 overseas projects and 4,000 potential American investors on file. Most investors would be firms interested in joint ventures to increase their potential worldwide sales territory or improve their efficiency and competitiveness domestically and abroad; perhaps even to secure a necessary component or raw material for their American production.Investor information service The investor information service is a series of kits on OPIC countries that are available by individual country or by regions. It is an excellent way to study the potential in an area for joint ventures or investment opportunities at a very reasonable cost. Relative  american investors  country projects  overseas projects  sales territory  opic  necessary component  worldwide sales  developing country...
Read more

FORECASTING EXCHANGE-RATE MOVEMENTS

FORECASTING EXCHANGE-RATE MOVEMENTS In the previous section we looked at the general law of supply and demand, showed how governments intervene to manage exchange-rate movements, and explained how inflation and interest rates can be important determinants of exchange rates. In this section we survey data that can be monitored in order to get an idea of what will happen to exchange-rate values. As the preceding discussion elaborates, a variety of factors influence exchange-rate movements. Managers must be able to analyze these factors in order to have a general idea of the timing, size, and direction of an exchange-rate movement. However, prediction is not a precise science, and many things can cause the best of predictions to differ significantly from reality. For freely floating currencies, the law of supply and demand determines market value. However, very few currencies in the world are freely floating; most are managed to a certain extent, which implies that governments need t...
Read more