Collecting Data Fairly: Privacy, Consent, Timing and Cost

0:00A class plans a survey of how much students at their school sleep. How can they collect the data fairly?

0:07Their first draft asks for a name, home address, phone number, age and hours of sleep last night.

0:15A common mistake is collecting names and details just in case. Each is more personal data to protect.

0:22Privacy means people control who sees their details. This survey needs no name, address or phone number, so they go.

0:31Now the form says not to write a name, so answers are anonymous: no one can tell who gave each answer.

0:39Consent means agreeing to take part after being told what the data is for, so the form says why, that it is a choice, and asks people to agree.

0:50Timing matters: after a holiday, a sleep survey the next morning can give odd answers, so the class picks an ordinary school week.

0:59The population is the whole group studied, here all 600 students. A sample is the part you actually ask.

1:08Each form takes about 3 minutes. Asking everyone takes 600 times 3, which is 1,800 minutes, or 30 hours.

1:19A sample of 60 takes 60 times 3, which is 180 minutes, or just 3 hours.

1:27A bigger sample is usually more reliable but costs more, so the class picks 60 students at random, each with the same chance.

1:37To collect data fairly, ask only what is needed, keep answers anonymous, get consent, pick a fair time, and weigh cost against sample size.