Difference between Direct Personal Investigation and Indirect Oral Investigation

Direct Personal Investigation and Indirect Oral Investigation are two of the many methods of collecting primary data.

What is Direct Personal Investigation?

Direct Personal Investigation or Personal Interview is a method of collecting primary data through which the investigator contacts the informant directly to collect data by conducting on-the-spot enquiry. He/she goes to the field personally, contacts the respondents, and convinces them to give the information required for the investigation. This method provides the interviewer or investigator with an opportunity to explain the study and answer the queries of the respondents. The investigator can also ask the respondent to expand the answers that are particularly essential for the investigation. Besides, the visual reactions of the respondents can also provide supplementary information to the interviewer.

For example, Body Shop wishes to conduct a statistical enquiry regarding the body shower gel used by people of Delhi NCR. For this, the company will select some investigators, who will approach the people living in Delhi NCR and collect the essential data. In such cases, it is essential that the investigator has a keen sense of observation about the area in which information is to be collected. Besides, the investigator must be polite, courteous, tactful, skilful, neutral, and accurate.

What is Indirect Oral Investigation?

Indirect Oral Investigation is a method of collecting primary data through which the investigator approaches third parties who are in possession of required information about the subject of enquiry. It is used when the area of investigation is large or the respondents feel reluctant in parting information with the investigator due to some reasons. Under this method, the investigator prepares a small list of questions related to the investigation, and then asks questions from different persons and records their answers. The person from whom these questions are asked is known as a witness. Usually, the police department and enquiry committees appointed by the government conduct this type of enquiry.

For example, we want to study the number of students in a college who drink alcohol. For this purpose, the investigator cannot get information through direct personal investigation because the students may not provide correct information, as drinking alcohol is regarded as a bad habit. Therefore, to get information, the investigator has to contact the people who are close to the respondent, like their friends, relatives, neighbours, or any other person who might know the information. 

Difference between Direct Personal Investigation and Indirect Oral Investigation

The difference between Direct Personal Investigation and Indirect Oral Investigation are as follows:

Basis	Direct Personal Investigation	Indirect Oral Investigation
Meaning	It is a method of collecting primary data through which the investigator contacts the informant directly to collect data by conducting an on-the-spot enquiry.	It is a method of collecting primary data through which the investigator approaches third parties who are in possession of required information about the subject of enquiry.
Coverage	This method is appropriate for a limited area.	This method can be used to cover a broad range of investigations.
Originality	In this method, the data collected is original in character as the data is collected directly from the source.	In this method, the data collected lacks originality as the data is collected indirectly from the respondents.
Accuracy and Reliability	The information collected under this method is more reliable and accurate.	There is a risk of unreliable and inaccurate information because of the indirect collection of data.
Cost	This method is costlier.	When compared with the direct personal investigation method, this method is cost-effective.