Sampling Techniques Introduction

1. What is a population?

• Everyone in the school

• A sample of students

• Data collected by a teacher

• None of the above

Answer explanation

A population refers to the entire group being studied. In this case, 'Everyone in the school' represents the complete population, while the other options describe subsets or unrelated data.

2. What is a census?

• Data from every member of a population

• A survey for part of the population

• A biased sampling method

• A statistical test

Answer explanation

A census collects data from every member of a population, providing a complete overview, unlike surveys that sample only part of the population. This makes the first choice the correct answer.

3. What is a sampling frame?

• The list of people from whom we draw a sample

• A photograph of the sample

• A type of biased sample

• None of the above

Answer explanation

A sampling frame is the list of people from whom we draw a sample. It serves as the source for selecting participants in a study, making it essential for accurate sampling.

4. What is a sample?

• The entire population

• A subset of the population

• All data collected twice

• A method of collecting data

Answer explanation

A sample is defined as a subset of the population, which means it includes a portion of the larger group being studied. This allows researchers to make inferences about the entire population without needing to collect data from everyone.

5. A sample is representative if...

• It's larger than the population

• It reflects the properties of the population

• It uses student volunteers

• It only includes the teacher's favorite students

Answer explanation

A sample is considered representative when it reflects the properties of the population, ensuring that the findings can be generalized. The other options do not guarantee this representation.

6. What is simple random sampling?

• Every member has an equal chance of being selected

• Selecting people at regular intervals

• Only selecting people from one group

• Sampling until the teacher is satisfied

Answer explanation

Simple random sampling means that every member of the population has an equal chance of being selected. This ensures that the sample is representative and reduces bias, making the correct choice the first option.

7. Systematic sampling...

• Selects every nth member from the frame

• Is always biased

• Uses quotas

• Samples the entire population

Answer explanation

Systematic sampling involves selecting every nth member from a population frame, ensuring a structured approach to sampling. This method is not biased by design and does not use quotas or sample the entire population.

8. Stratified sampling...

• Groups the population, then samples proportionally from each group

• Samples only one group

• Is another name for convenience sampling

• Selects every 10th person

Answer explanation

Stratified sampling involves dividing the population into distinct groups (strata) and then sampling from each group proportionally. This ensures representation from all segments, making the correct choice the first option.

9. Quota sampling is used when...

• The sampling frame is unknown

• Everyone is included

• Only random sampling is allowed

• The population is small

Answer explanation

Quota sampling is used when the sampling frame is unknown, allowing researchers to select participants based on specific characteristics without needing a complete list of the population.

10. A biased sample means...

• It's collected randomly

• It doesn't fairly represent the population

• It includes everyone equally

• It's always large

Answer explanation

A biased sample does not fairly represent the population, meaning certain groups may be overrepresented or underrepresented. This can lead to inaccurate conclusions about the entire population.