Sampling Techniques

What are the two main types of samples?

Probability and non-probability samples.

What is a probability sample?

A sample where each member has a known chance of being selected.

How are probability samples selected?

Randomly.

Are probability samples more or less biased?

Less.

What are the four types of probability sampling?

Simple random, stratified random, cluster, systematic.

What is a simple random sample?

Every member has an equal chance of being selected.

What is the probability formula for simple random sampling?

Sample size ÷ population size.

What is a key advantage of simple random sampling?

Fairness (equal chance).

What is a key disadvantage of simple random sampling?

Time-consuming and costly.

What is stratified sampling?

Dividing the population into groups and sampling from each.

What is the key benefit of stratified sampling?

Ensures representation from all groups.

What is a disadvantage of stratified sampling?

Requires identifying all groups.

What is cluster sampling?

Dividing the population into groups and selecting entire groups.

What is a key advantage of cluster sampling?

More efficient and less costly.

What is a disadvantage of cluster sampling?

Less representative.

What is systematic sampling?

Selecting members using a fixed interval with a random start.

What makes systematic sampling a probability sample?

The random starting point.

What is a key advantage of systematic sampling?

Most efficient.

What is a key disadvantage of systematic sampling?

Prone to bias due to human involvement.

What is a non-probability sample?

A sample where members do not have a known chance of selection.

Are non-probability samples random?

No.

Are non-probability samples more or less biased?

More.

What are the four types of non-probability sampling?

Quota, judgment, snowball, convenience.

What is quota sampling?

Dividing the population into groups and selecting based on quotas.

What makes quota sampling non-probability?

Human choice in setting quotas.

What is judgment sampling?

The researcher selects participants based on their judgment.

Why use judgment sampling?

To target people best suited to answer the research question.

What is snowball sampling?

Participants recruit other participants.

When is snowball sampling useful?

When the population is hard to reach.

What is convenience sampling?

Selecting the easiest available participants.

What is the main advantage of convenience sampling?

Fast and inexpensive.

What is an advantage of probability sampling?

More representative and less biased.

What is a disadvantage of probability sampling?

More costly and time-consuming.

What is an advantage of non-probability sampling?

Faster and cheaper.

What is a disadvantage of non-probability sampling?

More biased and less generalizable.

What is sampling error?

Error from using a sample instead of the full population.

Does a larger sample always reduce sampling error?

No.

What is researcher error?

Errors from poor research decisions.

What is population definition error?

Misidentifying the population.

What is sampling frame error?

Excluding people from the sampling pool.

What is instrument error?

When the tool does not properly measure what it should.

What is respondent error?

When respondents are unwilling or unable to answer.

Which error does reducing survey resistance address?

Respondent error.

Which error does optimizing question structure address?

Instrument error.

Which error does sharpening question wording address?

Instrument error.

Which error does arranging question order address?

Respondent error.

Which error does pretesting address?

Researcher error.

Which error does optimizing scales for analysis address?

Instrument error.

Which error does optimizing scales for comparison address?

Instrument error