Method of Collection of Primary Data:
There are various methods of collecting primary data which are as follows:

1. Direct Personal Interview:
In this method, the investigator or his agent collects the data by asking the questions individually. There is face to face contact between the respondent and the interviewer. This method is suitable:

a) When the area of inquiry is limited.
b) When the data is to be kept secret.
Merits:
a) The data obtained by this method are pure and original in character.
b) The investigator can clarify any doubts during the interview.
Demerits:
a) This method takes a lot of time so, it is an expensive method.
b) There is a chance of getting biased information.

2. Indirect Personal Interview:
In this method, the investigator does not directly ask the questions to the persons who are directly concerned with the problem. The investigator obtains the necessary information by contacting the third person who is familiar with the problem. The third person is said to witness. This method is suitable:

a) When the direct sources of information are not available.
b) When the informants are unwilling to give the correct information.
Merits:
a) It can cover a wider area very easily.
b) This method is cheaper, requires less time, money and labour
Demerits:
a) The witness may be biased to provide accurate information.
b) The selected informants may not be appropriate for people to answer the questions.

3. Information from Corresponds.
In this method, the investigator appoints local agents or correspondence in different parts or field of enquiry to collect information. These correspond collected and send to the central office. This method is suitable for:

a) Newspaper agencies, televisions agency for regular information.
Merits:
a) The information through this method is accurate.
b) This method is cheaper and less time-consuming.
Demerits:
a) Information sent by agents may not be reliable.
b) It is difficult to check the accuracy of the data.

4. Mail Questionnaire.
In this method, the investigator prepares a questionnaire (a set of questions). The questionnaire is sent to the various informants by post or mail. They are requested to answer the questions and post back to the indicator. This method is suitable:

a) When the field of investigation is large.
b) When the investigator requires quick result at low cost.
Merits:
a) This method is cheaper, saves time and labour.
b) The information can be collected from very far areas.
Demerits:
a) There is a high degree of non-response error.
b) Informants may feel fear to provide information.

5. Schedule sent through Enumerator.
In this method, the enumerators go to the informants personally with the schedule (a list of questions) and fill off the list of questions in their own handwriting by interviewing the informants. Population census in Nepal is conducted by this method. This method is suitable:

a) When the informants are illiterate
Merits:
a) The results obtained by this method are reliable and accurate.
b) Some additional information can also be obtained.
Demerits:
a) This method is more expensive.
b) The enumerators should be well trained, skilled and tactful. Otherwise, data may not be correct.

Problems in Primary Data Collection:

1. The informants may be uneducated and uncooperative. Thus, relevant and accurate information may not be collected.
2. If there is no transportation facility, the investigator may take the information without interviewing the informants.
3. The real facts of the data are not available due to the different conclusions given by the different informants about the same topic.
4. The limitation of time and money is the other problem involved in primary data collection.
5. Only a few questionnaires are sent back to the investigators by informants while using mail questionnaire method. So, accurate data can’t be expected.
6. Due to the shame, hesitate, fear of respondents, the investigator may not be collected with reliable information.