Distinguish between a population and a sample and investigate techniques for collecting data, including census, sampling and observation (VCMSP297)

LO: To investigate different techniques for collecting data.



Know:

  • What the definition of census is and what is the advantage over sampling.

  • What the definition of sampling is and what is the advantage over census.

  • What the definition observation is.

Understand:

  • That there are different ways of collecting data, each with their positives and negatives.

Do:

  • I can use different survey techniques to collect data.

Elaborations

  • identifying situations where data can be collected by census and those where a sample is appropriate

  • investigating the differences between convenience, judgemental and simple random sampling from a population

Visual Representations

Teaching Notes

There are 2 general techniques for collecting data, Census and Sampling.

Census – a census is when you collect data for every member of the group from the data set.

Sampling (sample) – a sample is when you collect data for a selected members of the group.

Positives and Negatives

 

Positives

Negatives

Census

+ More accurate because you have to survey everyone

–          Takes a lot of time to survey everyone

Sampling

+ Much quicker to survey a select few rather than the whole population

–          Less accurate as the sample might not be representative of the whole.

Sampling (sample) – a sample is when you collect data for a selected members of the group.

Positives and Negatives

Teaching Ideas

  • explain the relationship between a census, a representative sample, sample size, and a population (e.g.,“I think that in most cases a larger sample size will be more representative of the entire population.”

Collecting Data Videos

Practise Questions

Year 8 Big Ideas

Exercise 9A pg. 313 Now Try These: Q. 1-3

My Maths 8

Exercise 9A pg. 459 Q. 1-15

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