Probability and Statistics - Lecture 3: Sampling Techniques

Vocabulary-style flashcards covering various probability and non-probability sampling techniques from Lecture 3 of the Probability and Statistics (DIT 164) course.

Simple Random Sampling

A technique that gives every item in the population an equal chance of being selected to be part of the sample.

Simple Random Sampling with Replacement (SRSWR)

A type of sampling where a selected unit is returned to the population before the next one is selected, meaning the same unit can be selected more than once.

Simple Random Sampling without Replacement (SRSWOR)

A type of sampling where once a unit is selected, it is not replaced, and each unit is selected only once.

Methods of Simple Random Sampling

Techniques used to select items which include Balloting, Table of Random Numbers, and Computer Selection.

Stratified Sampling

A technique where the population is divided into smaller groups called strata, and a determined number of items are selected from each stratum to form the sample.

Stratified Sampling Methods

Includes Equal Allocation and Proportional Allocation.

Systematic Sampling

A sampling technique in which every kth item is selected from the population under study to form the required sample.

Sampling interval (k)

The interval used in systematic sampling, calculated as $k = \frac{N}{n}$ where $N$ is the population size and $n$ is the sample size.

Cluster Sampling

A technique where the population is divided into areas called clusters; a determined number of clusters is selected at random, and all items in those clusters are observed.

Multistage Sampling

An extension of cluster sampling where the population is divided into clusters, and some sampled clusters are again subdivided into smaller groups until the required sample size is obtained.

Judgment Sampling

A non-probability technique where sampling is done according to the personal judgment or discretion of the researcher.

Quota Sampling

A non-probability technique where an interviewer is instructed to collect data from an assigned number of items (quota) from several groups, such as age, sex, or income.

Chunk Sampling

A non-probability sampling technique under which the interviewer plays no role in the selection of the sample.

Convenience Sampling

A non-probability technique where samples are chosen with the sole concern for easy access or being easily obtained.

Snowball Sampling

A technique used for small specialized groups (e.g., albinos) where the first respondent is identified and others are obtained via referrals from previous ones.