Obtaining and Evaluating Secondary Data

Study Tip: When evaluating a dataset, always check if it is "compiled" or "raw." Using compiled data can save time, but using raw data may give you more control over the specific transformations required for your unique research question.

Major Sources of Secondary Data

To find the right data, you must know where to look. Secondary data sources are generally grouped into three broad categories: survey-based, documentary, and multiple-source data.

1. Survey-Based Secondary Data

These sources consist of data collected via previous survey strategies, often using questionnaires that have already been analyzed for their original intent. There are three distinct subtypes:

• Censuses: These are typically conducted by governments and are unique because participation is often obligatory. Because they aim for comprehensive coverage, they provide excellent insights into entire populations.
• Continuous and Regular Surveys: These are surveys (excluding the census) that are repeated over set intervals to track changes over time.
• Ad hoc Surveys: These are one-off, specific surveys often conducted by independent researchers or organizations to address a particular subject matter.

2. Document Secondary Data Sources

Documents serve as durable repositories of information that endure physically or digitally. Unlike the spoken word, these records allow researchers to transpose data across both time and space, enabling re-analysis for purposes entirely different from the original collection. These sources include:

• Text
• Audio
• Audio-visual media

3. Multiple-Source Secondary Data

This category involves datasets that were created by combining different datasets (which could be documents, surveys, or a mix of both) prior to the researcher's access. These are categorized by their temporal nature:

• Snapshot datasets: Data representing a specific point in time.
• Longitudinal datasets: Data collected over a continuous period of time, allowing for trend analysis.
• Continually updated datasets: Data that is constantly refreshed with new information.

Evaluating Your Choice: Pros and Cons

Before committing to a secondary data source, you must weigh its advantages against its inherent risks.

Worked Example: The Researcher's Dilemma

Scenario: A researcher wants to study the impact of inflation on household spending habits in a specific country over the last 10 years.

• Option A (Primary Research): Conduct a massive nationwide survey every year for 10 years.
  • Verdict: Extremely high cost and resource requirement.
• Option B (Secondary Research): Access a longitudinal dataset from a government agency that has been conducting continuous and regular surveys on consumer spending.
  • Verdict: Much more efficient. However, the researcher must evaluate if the government's definition of "household spending" matches their own research definition.

Exam Alert: If asked to justify the use of secondary data, do not just say it is "cheaper." Use the formal criteria: mention availability, accessibility, and the balance of cost and benefits.