Sampling Techniques and Bias

What is the name of the entire group under consideration?

What is a smaller group taken from the larger group called?

This sampling technique numbers everyone in the population and then uses technology to generate random numbers that are chosen. Everyone in the population has an equal chance of being selected.

• Simple Random Sample (SRS)

• Cluster Sampling

• Stratified Sampling

• Systematic Sampling

This type of sampling groups people into cluster (usually by area). Some clusters are then randomly selected and everyone in the cluster is surveyed.

• Simple Random Sampling

• Cluster Sampling

• Stratified Sampling

• Systematic Sampling

This sampling method separates the population by naturally occurring groups (grades, race, etc), then random sampling is used to selected people from within every group.

• Simple Random Sampling

• Cluster Sampling

• Stratified Sampling

• Systematic Sampling

This sample technique uses population size and desired sample size to predetermine a systematic number (such as every 100th person). Then a random number generator is used to select the starting value. All other people in the sample are chosen by adding that systematic number to the starting value.

• Simple Random Sampling

• Cluster Sampling

• Stratified Sampling

• Systematic Sampling

If your sample is taken from only those who volunteer to take your survey, you might have more strong opinions represented. This is known as:

• Voluntary response Bias

• Undercoverage

• Questionnaire Bias

• Convenience Sampling

This occurs when a portion of the population is left out of the sampling technique. This can occur by accident or by poor design.

• Undercoverage (Size Bias)

• Voluntary Response Bias

• Convenience Sampling

• Non-response Bias

This occurs when your survey may be filled with very technical words or word that are hard to understand and therefore makes it difficult for the reader to respond. 

• Questionnaire Bias

• Non-response Bias

• Undercoverage

• Convenience Sampling

• To obtain a sample of households, a television rating service dials numbers taken at random from the telephone book. What type of bias is this?

• Undercoverage

• Convenience Sampling

• Questionnaire Bias

• Voluntary response Bias