# Cluster vs. Stratified Sampling: What’s the Difference?

Cluster sampling divides a population into groups, then includes all members of some randomly chosen groups. Stratified sampling divides a population into groups, then includes some members of all of the groups.

A technique called cluster sampling divides the target population into various clusters. To create the target sample, a second stage or multiple stages of sampling may be used, or some of these clusters may be randomly chosen for sampling. Cluster sampling can be done in one step, two steps, or more steps, depending on how many steps are needed to create the desired sample. This sampling technique is very affordable because it requires little work to create the samples and is also simple to use.

A large population is split into distinct, homogeneous strata using the probability sampling technique known as stratified sampling, and then individuals from each of these strata are randomly chosen to make up a sample. Each sample’s components will be unique, giving everyone in the population an equal chance to participate in these samples. Separation based on factors such as age, religion, nationality, socioeconomic status, and qualifications, among others can be done using this sampling technique.

## What is stratified sampling?

A population’s members are grouped together into a homogenous group using the data collection technique known as stratified sampling, also known as random quota sampling, or a similarly distributed group of people. Researchers can pick participants at random to create smaller groups from this pool of participants. For the purpose of forming the homogeneous group that researchers are after, these participants must adhere to predetermined criteria.

## What is cluster sampling?

Cluster sampling is a technique for gathering research data that uses random clusters from a given population as research samples. For an experiment, this kind of sampling could take place just once, or it could involve segmenting the chosen populations into additional subgroups. According to the needs of a project, researchers can choose between two and four different stages of separation to produce larger or smaller clusters. Participants don’t need to follow any rules because this selection is random and there are no requirements.

## Cluster vs. stratified sampling

Although both of these techniques are frequently used in research, it can be useful for people to compare their differences and similarities to decide which is most suitable for their use. The following are the primary distinctions between stratified sampling and cluster sampling:

### Group differences and creation

Users may have already been sorted into preexisting groups of people known as strata when using stratified sampling. Strata distinguish themselves from being a random sampling by identifying a class of members who have satisfied predetermined entry requirements. With cluster sampling, you can anticipate that participants have not undergone any presorting evaluations or class designations and that the selection process is random. No classes exist, and the only obstacles to membership are the randomly selected clusters determined at each stage.

Despite differences at the group level, both approaches help to achieve the same end result of producing well-rounded research. Regardless of whether you select cluster sampling or stratified sampling, your data can be organized well for the best readability.

### Times of use

Another way that cluster sampling and stratified sampling differ is in the method of selecting the most appropriate grouping. You may decide to use a stratified sample method for samples that are heterogeneous, meaning they are dynamic due to a number of predetermined factors. As an alternative, if your sample population is homogeneous, you might think about employing a cluster sample method to increase efficiency without jeopardizing the project’s integrity.

### Purposes

The purpose and application of each sampling technique are typically taken into account when researchers design an experiment. Users can narrow the population with the aid of stratified sampling, producing more focused and accurate data for in-depth areas of study. Due to its straightforward design structure, cluster sampling can result in higher levels of efficiency and serve a more useful purpose. It is also more affordable. By employing a less stringent method of grouping, researchers may be able to maximize their time and investment.

### Determination of bifurcation

In research, bifurcation means the division process of different groups. Typically, groups are divided into a minimum of two groups, and the parameters of the experiment may require additional split stages. Researchers can control the various factors that lead to the separation process in stratified groupings, making them the source of the bifurcation. Instead, cluster sampling is completely random and doesn’t follow a manufactured separation process.

## Tips for choosing your sampling strategy

Researchers need a sampling plan for experimental design that is in line with their objectives and supplies them with pertinent data sets. The following advice will assist you in selecting an efficient sampling plan for your study:

## Example of cluster vs. stratified sampling

The distinctions between cluster and stratified sampling in a laboratory setting are illustrated by the examples below:

### Cluster sampling example

The ability of purple-winged moths to withstand temperatures lower than 50 degrees Fahrenheit is being studied by a research team. To complete the project by the deadline, the sampling must happen quickly. Stakeholders give the research team permission to use a cluster sample structure to be both economical and effective because they want to examine purple-winged moths at all stages of development against the elements.

### Stratified sampling example

A researcher is assessing the effectiveness of a prescription drug for treating chronic pain. They want to test people who are 65 years of age or older and those who have experienced discomfort for more than five years as they are currently designing the experiment. The experiment’s cluster or stratified sampling is under consideration by the researcher. They conclude that a stratified sampling method is the most effective approach because it can help ensure that the results reflect the complexity and accuracy of the data for the target population.

## FAQ

Why is a stratified sample better than a cluster sample?

As sampling is carried out on a population of clusters in cluster sampling, a cluster or group is regarded as a sampling unit. In Stratified Sampling, elements within each stratum are sampled. In Cluster Sampling, only selected clusters are sampled. In Stratified Sampling, a random sample is taken from each stratum.

What is the difference between sampling and stratified sampling?

The primary distinction between cluster sampling and stratified sampling is that with cluster sampling, your population is divided into natural groups. You might be able to segment your data, for instance, into groups that naturally exist, such as city blocks, voting districts, or school districts.