Data Collection Methods

Before going through the time and expense of collecting primary data, one should check for secondary data that previously may have been collected for other purposes but can be used in the immediate study. Secondary data may be internal to the firm, such as sales invoices and warranty cards, or may be external to the firm such as published data or commercially available data. The government census is a valuable source of secondary data. Secondary data has the advantage of saving time and reducing data gathering costs. The disadvantages are that the data may not fit the problem perfectly and that the accuracy may be more difficult to verify for secondary data than for primary data. Some secondary data is republished by organizations other than the original source. Because errors can occur and important explanations may be missing in republished data, one should obtain secondary data directly from its source. One also should consider who the source is and whether the results may be biased. There are several criteria that one should use to evaluate secondary data.

 Whether the data is useful in the research study.

 How current the data is and whether it applies to time period of interest.

 Errors and accuracy - whether the data is dependable and can be verified.

 Presence of bias in the data.

 Specifications and methodologies used, including data collection method, response rate.

 Quality and analysis of the data, sample size and sampling.

 Objective of the original data collection.

 Nature of the data, including definition of variables, units of measure, categories used, and relationships examined.

Often, secondary data must be supplemented by primary data originated specifically for the study at hand. Some common types of primary data are:

 demographic and socioeconomic characteristics

 psychological and lifestyle characteristics

 attitudes and opinions

 awareness and knowledge - for example, brand awareness

 intentions - for...