WHAT ARE THE POPULATION AND THE SAMPLE OF AN INVESTIGATION? - SCIENCE - 2025

The population and the research sample are the groups of individuals that share common characteristics and are analyzed by statistics in order to obtain data of interest.

Statistics alone could not make sense as an exact science. For this reason, both populations and samples are essential for their existence.

A population can be understood as the set of individuals or elements on which observations will be made.

This group is finite or infinite and can be made up of people, publishers, television programs, animals, plant species, among others (Punta, 2017).

The sample, for its part, is a subset derived from the population on which the research is to be carried out (David, 2017).

This is selected using different methods that include randomness, stratification or systematization. The process of selecting a sample is known as sampling.

Sampling uses mathematical and logical formulas to select a representative segment of the population. Also, it establishes parameters, procedures and criteria to make said selection.

Sampling is responsible for choosing a group of individuals who can accurately represent certain data common to the entire population.

Definition of the concept of population

The population is the general or total group of elements, individuals or measures that share common features within a given context.

These traits must be taken into consideration when selecting the individuals that will be part of the study population (BMJ Publishing Group, 2017).

population characteristics

Any statistical study must take into account the following features or parameters when choosing the population to be studied:

Weather

Time is the chronological moment in which the population to be studied is found. It is important to determine if the population you want to study is located chronologically five years ago or, on the contrary, is in the present.

A statistical study can study populations for years and generations, with the aim of identifying relevant information over time.

Quantity

This item refers to the number of people that make up a population, that is, its size.

Population size is one of the most important items in an investigation, as it will determine the size of the study segments (samples).

On the other hand, the size of the study population will depend on the availability of time and resources by the research entity.

Space

Space is the physical place where the population to be studied is located. Like the size of the population, the extent of the study area will depend on the time and resources that the researcher has on hand.

Homogeneity

This item talks about the similarity between the traits of the selected members in relation to the research topic

Definition of the sample concept

A sample is a finite and important segment or subset taken from a population. Within any broad-spectrum investigative process, it is essential to select a sample.

This is because the study of large groups of individuals requires a high investment in money, time and effort (Inc, 2017).

Samples tend to be enough to get a picture of the entire population. When rigorously chosen, your study can yield data that is representative of the general population.

Sampling

A sample can be taken in different ways, depending on the interests of the researcher. The quality of the study and the features to be analyzed will determine the type of sample to be chosen (López, 2004).

Samples can be chosen with the help of the following methods:

1 - Random: this sampling method is based on the unpredictable selection of members of a population. It is characterized because all members of the population have equal opportunities to be part of the sample.

2 - Stratification: stratification consists of the division into groups or strata of a population. These groups are formed taking into account the traits to be investigated. Each of these strata is selected in a proportionate way in relation to the population.

3 - Systematic: this sampling method starts from the identification of a pattern to select individuals from a population. The selection criteria established by this method is almost always numerical. For example, a researcher might interview one woman for every ten who enter the supermarket.

Size of a sample

The size of a sample refers to the number of individuals that will be included within it. Thus, the number of individuals included within the sample will depend on the precision that is to be achieved with its study.

Ideally, larger samples should be studied, as these will yield data more accurately on the general population.

However, the size of the sample is subject to the availability of time and resources by the researcher.

Most experienced researchers recommend that a sample contain a minimum of 30 individuals. However, depending on the type of research, samples can be made up of 10 or 20 percent of the general population.

Advantages of studying a sample

Studying a sample instead of studying a population can offer the following advantages:

- Time: saves time when studying a smaller group of individuals.

- Costs: by requiring a smaller amount of resources, it also allows saving costs within the research process.

- Feasibility: studying the entire population is almost always an unlikely task. When studying a sample, it is guaranteed that all members of the sample will be analyzed.

- Gradual increase: the size of the sample can be increased as resources and time that can be invested in research increase. This allows to regulate the precision of an investigation, something that does not happen when studying a population.

- Specific selection: makes it possible to choose a group of homogeneous characteristics, increasing the possibilities of analyzing the most relevant features or characteristics in a specific way.

References

1. BMJ Publishing Group, L. (2017). Populations and samples. Obtained from Population: bmj.com
2. (2017). Statistics Solutions. Retrieved from What is the Difference Between Population and Sample ?: statisticssolutions.com
3. Inc, W. (2017). Business Dictionary. Retrieved from statistical sample: businessdictionary.com
4. López, PL (2004). POPULATION SAMPLE AND SAMPLING. Zero point.
5. Punta, U. d. (2017). Mathematics Module III. Obtained from Population and Samples: contentsdigitales.ulp.edu.ar.