Basic Concepts
What is a sample?
A subset of individuals chosen from a larger population for the purpose of statistical analysis.
Name a type of probability sampling.
Simple random sampling.
Why is determining the correct sample size important?
To ensure the sample is representative of the population and the results are statistically significant.
What is one advantage of using a sample over a census?
It is less time-consuming and less expensive.
Why is sampling used in opinion polls?
To gather information about the opinions of a population without surveying everyone.
What is the main purpose of sampling?
To make inferences about a population without having to survey the entire population.
What is stratified sampling?
A method of sampling that involves dividing a population into subgroups (strata) and taking a sample from each stratum.
What is the margin of error?
An expression of the amount of random sampling error in a survey's results.
Name a disadvantage of convenience sampling.
It can lead to biased results because it does not represent the entire population.
How is sampling used in quality control?
By testing a sample of products to infer the quality of the entire batch.
What is a population in the context of sampling?
The entire group of individuals or instances about whom the study is concerned.
Define cluster sampling.
A sampling technique where the entire population is divided into groups, or clusters, and a random sample of these clusters is selected.
Name one factor that affects sample size determination.
Population size.
What is an advantage of stratified sampling?
It ensures that different subgroups are adequately represented in the sample.
In a humanitarian research, why might a sample be used instead of the entire population?
Because it is often impractical or unethical to study the entire population.
Define "sampling frame"
A list or other device used to define a researcher’s population of interest.
What is systematic sampling?
A method of sampling where every nth individual is selected from a list or queue.
What is the confidence level in the context of sample size determination?
The probability that the value of a parameter falls within a specified range of values.
What is a disadvantage of cluster sampling?
It can increase sampling error if clusters are not homogeneous.
Give an example of cluster sampling in an educational project or research.
Selecting entire classrooms or schools as clusters to study educational outcomes.
What is a sampling error?
The error caused by observing a sample instead of the whole population, which can lead to differences between the sample statistic and the actual population parameter.
Name a type of non-probability sampling.
Convenience sampling.
How do you calculate the sample size for a proportion?
Let the class show the formula!
Name an advantage of using a larger sample size.
It reduces the margin of error and increases the reliability of the results.
How is stratified sampling useful in humanitarian needs assessments?
It ensures different subgroups within the affected population (e.g., different age groups, genders, or geographic regions) are adequately represented in the sample.