Questionnaires & Sampling

What is a questionnaire?

a document or form with a series of questions that standardise the variables under study, designed to generate the data sought by the research project

What is the purpose of a questionnaire in statistics?

To collect information from individuals through a series of structured questions, either open or closed, often used in surveys.

What are the two main types of questions in a questionnaire?

Open-ended questions and closed-ended questions. But there are also mixed, which combines open and closed options, and scaled responses, which are closed-ended questions in which the options are designed to determine the intensity of the respondent’s feelings by including a scale of some kind.

What is a closed-ended question?

A question that limits responses to pre-established options, allowing for easy quantification and analysis.

• Dichotomous: two possible answers.

• Multiple: more than two alternative answers.

• Single : responseonly one of the options can be ticked

• Multi-response: more than one option can be ticked for the same question

What is an open-ended question?

A question tht allows the respondent to answer freely, giving more qualitative detail but harder to analyze statistically.

What is sampling in statistics?

The process of selecting a subset of individuals from a population to estimate characteristics of the whole population.

What is a population in statistical terms?

The entire group of individuals or items that is the subject of a statistical study.

What is a sample?

A subset of the population selected for analysis.

What is the purpose of using a sample instead of the entire population?

To save time and resources while still obtaining accurate and representative information.

What are some sampling errors?

• Random error

• Systematic or bias error

Two types of Sampling methods

• Probability sampling: each element of the population has a known non-zero probability of being selected for the sample

  • Types of probability sampling: simple random sampling, systematic sampling, stratified sampling, cluster or group sampling

• Non-probability sampling: sampling units are not selected at random, but are chosen based on the judgement of the interviewer or researcher

  • Types of non probability sampling: convenience sampling, criterion sampling, quota sampling, snowball sampling