Primary and secondary data
Primary and secondary data.
- Primary data are collected first-hand for the investigation. Secondary data were collected by someone else or for an earlier purpose.
- Decide from the investigator’s point of view. Check relevance, date and collection method whichever type you use.
Example 1
Maya measures the heights of plants for her investigation. Are these primary or secondary data for Maya?
Maya collected the measurements herself for this investigation.
Example 2
Leo uses rainfall figures from a published weather report. Are these primary or secondary data for Leo?
Someone else collected the figures before Leo used them.
Your turn
A class writes a questionnaire and collects the replies. Classify the data for the class.
Check answer
The class collected the responses directly.
Nina downloads population figures from a government website. Classify the data for Nina.
Check answer
The government collected and published the information.
A science teacher records temperatures. A student later uses the teacher’s results. Classify the data for the student.
Check answer
The student is using someone else’s measurements. The same readings were primary data for the teacher.
A shop owner times customers’ waits during her own study. Classify the data for the owner.
Check answer
She obtains the timings directly for the study.
Ravi analyses attendance totals from a school’s existing annual report. Classify the data for Ravi.
Check answer
He is reusing previously collected records. Secondary data are not automatically unreliable; check how and when they were collected.
A class writes a questionnaire and collects the replies. Classify the data for the class.
AnswerThe class collected the responses directly.
Nina downloads population figures from a government website. Classify the data for Nina.
AnswerThe government collected and published the information.
A science teacher records temperatures. A student later uses the teacher’s results. Classify the data for the student.
AnswerThe student is using someone else’s measurements. The same readings were primary data for the teacher.
A shop owner times customers’ waits during her own study. Classify the data for the owner.
AnswerShe obtains the timings directly for the study.
Ravi analyses attendance totals from a school’s existing annual report. Classify the data for Ravi.
AnswerHe is reusing previously collected records. Secondary data are not automatically unreliable; check how and when they were collected.