Introduction

Quantitative research is one of the fundamental scientific methods applied in the social and human sciences as well as in many other fields. Its purpose is to record, measure, and analyze phenomena in a standardized and objective way, so that reliable conclusions can be drawn about the population under study. It is usually conducted through the use of questionnaires, experiments, or statistical analyses, and it allows the researcher to identify trends, compare groups, and test theoretical hypotheses. At the same time, quantitative research is characterized by the fact that it is based on observations made at a specific point in time, which limits its potential for generalization. However, when combined with longitudinal research or supplemented by qualitative methods, it acquires significant weight and usefulness.

Research Methods: Qualitative and Quantitative

Research methods are divided into two main categories: qualitative and quantitative. Qualitative methods focus on the type and nature of a phenomenon, offering in-depth understanding, whereas quantitative methods aim at measurement and the correlation of variables. Although they follow different logics, they are often used in a complementary way, so as to provide a more complete picture of the research field.

Characteristics of Quantitative Research

The quantitative method follows a strictly predetermined design, with emphasis on validity, reliability, representativeness, and objectivity. Data are standardized so that they can be expressed in numerical form, which allows analysis through statistical techniques. In this way, theoretical hypotheses are empirically tested, and the findings can, under certain conditions, be generalized to the wider population. The main characteristics of the quantitative method include its structured and rigid form, the possibility of analyzing large samples, the identification of general trends, and the correlation of variables for the purpose of verifying hypotheses. It focuses on the measurement of theoretical concepts using tools such as standardized questionnaires, while the concepts themselves are empirically defined through appropriate indicators.

Types of Quantitative Methods

Quantitative research includes various methods, each with its own applications. In the experimental method, the researcher controls the conditions and studies the effects of specific factors. In the survey method, data are collected mainly through questionnaires, while in secondary research existing data are used from official agencies, statistical services, research centers, or universities. Finally, in content analysis, communication data such as texts or media are categorized and quantified in order to extract systematic conclusions.

Longitudinal Research

An important category of quantitative studies is longitudinal research, which is repeated over time and allows the study of changes. Panel studies examine the same individuals over a period of time, while cohort studies investigate different samples from the same population, such as the generation of the Polytechnic movement. Trend studies focus on the changes of political or social behavior through the comparison of different samples over time.

Sampling and Categories of Samples

In quantitative research, because collecting data from the entire population is often unfeasible, sampling is used. There are two main categories of samples: random and non-random. Random or probability samples ensure representativeness and allow generalization of results to the population. These include simple random sampling, systematic sampling, stratified sampling, and cluster sampling. On the other hand, non-random samples, such as convenience sampling, purposive sampling, quota sampling, and snowball sampling, are mainly used in descriptive research when complete randomization is not possible, but they do not allow strict generalization. In any case, an unavoidable issue is sampling error, which can be minimized through the application of proper techniques and by increasing the sample size.

Conclusion

Quantitative research is an indispensable tool in the scientific study of social and other phenomena. It provides the possibility for objective measurement, analysis, and interpretation of data, contributing to the formulation of reliable conclusions. Although it has limitations, such as rigidity and the need for large samples, its contribution is crucial for the generalization of results and the testing of theoretical hypotheses. When combined with qualitative methods, it offers a holistic approach to understanding complex social issues and constitutes a cornerstone for scientific progress.