Quantitative data are used when a researcher is trying to quantify a problem, or address the "what" or "how many" aspects of a research question. It is data that can either be counted or compared on a numeric scale. For example, it could be the number of first year students at Macalester, or the ratings on a scale of 1-4 of the quality of food served at Cafe Mac. This data are usually gathered using instruments, such as a questionnaire which includes a ratings scale or a thermometer to collect weather data. Statistical analysis software, such as SPSS, is often used to analyze quantitative data.
Qualitative data describes qualities or characteristics. It is collected using questionnaires, interviews, or observation, and frequently appears in narrative form. For example, it could be notes taken during a focus group on the quality of the food at Cafe Mac, or responses from an open-ended questionnaire. Qualitative data may be difficult to precisely measure and analyze. The data may be in the form of descriptive words that can be examined for patterns or meaning, sometimes through the use of coding. Coding allows the researcher to categorize qualitative data to identify themes that correspond with the research questions and to perform quantitative analysis.
Research topics may be approached using either quantitative or qualitative methods. Choosing one method or the other depends on what you believe would provide the best evidence for your research objectives. Researchers sometimes choose to incorporate both qualitative and quantitative data in their research since these methods provide different perspectives on the topic.
Example: You want to know the locations of the most popular study spaces on Macalester's campus, and why they are so popular. To identify the most popular spaces, you might count the number of students studying in different locations at regular time intervals over a period of days or weeks. This quantitative data would answer the question of how many people study at different locations on campus. To understand why certain locations are more popular than others, you might use a survey to ask students why they prefer these locations. This is qualitative data.