Primary versus secondary data


Understanding the Differences between Primary and Secondary data

Data collection is an important part of market research. Whether for understanding complex issues or answering questions and for hypothesis testing, researchers need to collect data. The data they collect for the purpose of research can be either primary or secondary data based on the source from which it was obtained. One primary difference between primary and secondary data is that while primary data is first-hand, secondary data is second-hand data.

In this post, we will highlight the most important differences between primary and secondary data.

Primary Data Definition:

Primary data means the first-hand data gathered by the researcher himself specifically for a study. It is also known as first-hand or raw data. The process of obtaining primary data can be a lot more complex than secondary data, apart from being time-consuming and labor intensive, and costly. However, in a large number of situations, the study cannot be carried out without gathering primary data. Specifically when you are trying to address a new situation or issue which has not been investigated previously. Primary data collection is carried out using mainly three methods: observational research, surveys, and experimental research.

Secondary Data Definition:

Secondary data or second-hand data is already available to the researcher and may not require further processing, unlike primary data. The secondary data may not be directly related to the problem the researcher is trying to investigate. It can be readily accessed from public databases or other similar sources. However, despite being second-hand data, secondary data can be reliable in most cases. It can also be less costly to obtain and process because of its easy availability. While secondary data collection is more affordable than primary data, the problem is that it may not completely meet the researcher’s need in a specific situation since another researcher collected it for a different purpose. Therefore, it might be useful only to a limited extent and may partially support the research process.

Main differences between primary and secondary data:

Primary DataSecondary Data
First hand dataSecond hand data
Can be used with confidenceMay require further analysis to derive conclusive results.
More reliable since collected for a specific purpose.May be collected for a different purpose and therefore less suitable or reliable for a different study.
Can be expensive.More affordable compared to primary data.
Available in crude formAvailable in refined form

Primary data is first-hand data or data collected for the first time for a specific purpose. Once it has been used in research and results published, it becomes secondary data if used for another study. There are primarily three methods of primary data collection – observational research, surveys, and experimental research. Moreover, since primary data is collected for the first time, it is original data. Sources of primary data include surveys, observations, experiments, questionnaires, personal interviews, etc. 

Secondary data is second-hand data that is obtained from existing sources of data or based on research that has been conducted previously. Sources of secondary data include government databases, government websites, books, journals, internal records, etc. the internet itself is a vast repository of secondary data. You can search for secondary data online easily and apart from sources of scholarly literature there are several databases including government and private sources that offer reliable secondary data in a highly refined format. You can search for related research easily using google scholar or other reliable resources like Jstor, Proquest, or other similar databases including university and college databases.

The researcher is usually more confident about using the primary data he has collected compared to the secondary data. The reason that one can easily rely upon primary data is that it has been collected from subjects directly for a specific purpose. On the other hand, secondary data cannot be used with as much confidence. It is because the secondary data was collected by some other researcher for some other purpose.  In order to derive conclusive results from secondary data, the researcher may need to analyze and process it to make it usable for his specific purpose. Since the secondary data was specifically collected for another study,  even if similar, it cannot be as suitable as primary data for the specific study under consideration.

The process of collecting primary data can be considerably expensive as compared to secondary data which may be readily available from various sources like public databases. One may need to invest in human resources and pay for the various channels he uses for collecting primary data. Apart from that, collecting primary data may take more time as compared to collecting secondary data. The process can be lengthier in the case of primary data when compared to secondary data.

Primary data is generally available in crude form and the researcher needs to refine it to make it usable and presentable. However, secondary data is available in a refined format like tables and graphs. Despite its disadvantages over primary data, secondary data can be highly useful in certain circumstances because of its availability and affordability.

Especially, when the time required to complete the research is limited, the researcher may need to rely more on resources that offer secondary data rather than collecting primary data in vast amounts. Apart from that, secondary data collection is also more economic compared to primary data. However, when it comes to originality and reliability, primary data is indisputably the more reliable choice and will provide more reliable results.