Data collection is the process by which researchers gather the information they need, the purpose of which is to conduct a study.

Data collection is a necessary step before conducting a statistical study. This is due to the fact that this data is needed to process the information and its subsequent interpretation.

It should also be noted that the data collected can be qualitative or quantitative. In the first case, we are referring to characteristics such as race, gender, profession, opinion on a particular topic, and others. Instead, quantitative data is numerical data. That is, those in which they can be measured, such as height, weight, income level.

Different sources can be used in collecting data, such as bibliographic sources (especially if the information is qualitative) or freely available databases. For example, a journalist can access information about the allocation of the state budget on his government’s transparency portal.

Data collection methods
The most important methods of data collection are as follows:

Interview
It consists of questions to the people involved in the research. These can be open-ended and/or closed-ended questions.

In the first case, the interviewee is required to talk in detail about a specific topic, such as how he or she felt during the first week in the new job.

On the other hand, closed-ended questions are those with a limited number of alternative answers, such as when customer service asks their users if their satisfaction level was very low, low, medium, high, or very high.

It’s important to keep in mind that the interview can take many forms: in person, online, or by phone.

Other data collection methods
In addition to the above, there are other methods that can help us extract more data:

Observation: The researcher assumes a viewer’s work on the subject of the study. This is to collect its characteristics. Imagine, for example, the case of a person who studies a species of bird. He then spends several hours a day observing how the animals of that species interact, as well as their relationship to the environment in which they live.
Surveys: These are a series of questions asked of a group of people. Unlike interviews, they do not require extensive interaction between interviewer and interviewee. Surveys can even be done by e-mail or through a computer system. Like an interview, you can have open-ended and closed-ended questions.
Focus Group: It consists of a group session in which information is gathered on a specific topic, such as a new product the company intends to release. It is a method widely used in market research.

Before choosing a data collection method, think about the advantages and disadvantages of each. For example, a telephone interview may give the interviewee more freedom in expressing his or her opinion because he or she is not meeting the interviewer face-to-face. However, there is the challenge of preparing short and direct questions so that the interviewee does not abandon the process.