00:01
We're looking at sampling bias and types of sampling bias, and we've got four scenarios.
00:08
And we want to note which type of sampling bias were guaranteed to get.
00:13
So the first scenario, we have a poll that's conducted by contacting people on landline phones.
00:27
And that's your first key right there.
00:29
And this is going to be under coverage bias.
00:32
And the reason for that is because under coverage bias occurs when a part of the population is excluded from your type of sample.
00:47
So here we're only talking to people with landline phones and not everyone has a landline phone.
00:52
So there's a chunk of the population not represented.
00:56
And then number two, we have a political poll that's administered by contacting people on landline phones.
01:02
Same scenario.
01:05
And they contacted 10 ,000 households.
01:08
But only 2366 out of 10 ,000 people agreed to speak.
01:17
So this, we have non -response bias.
01:29
So non -response bias occurs when survey participant is unwilling or unable to respond to a survey question or the entire survey.
01:38
And so here we have the almost 8 ,000 people is at 70 ,000.
01:44
7 ,000, over 7 ,000 people didn't respond to the survey...