Scientific research is a process of systematic data collection and analysis to figure out a solution to a problem.

Quantitative research is based on positivist paradigm, which advocates that reality will
surface precisely through logic and experiment. Accordingly, it strives to formulate universal laws for each field of scientific study.

The very first step of a research process is problem identification, which can be distilled from various sources including daily life, practical issues, findings of previous research, and relevant theories.

A well-defined quantitative research problem has to bear some certain features.
First, the variables in the problem have to explain a relation. Second, it has to be formulated as question. Accordingly, formulas such as “Is there a relation …?”, “What is the effect of …?”, and “Does it change …?” can be employed to construct a question for a research problem. Third, a research problem has to be suitable for analysis based on collected data, or it has to be testable. 

A hypothesis is the conversion of a research problem into a tangible form that can be examined and tested. Thus, a well-developed hypothesis should clearly point out the dependent and independent variables, their levels, the research model, and whether the relation or difference will be studied in that research.

Research design is the arrangement necessary to collect and analyze research data in the most economical way. There are two primary research designs often utilized for quantitative research studies, which are survey and experimental designs.

Survey serves to determine general tendency, attitude, or opinions of a population quantitatively or in numerical values by working on a sample chosen from that population.

Longitudinal study aims to collect data at least two or more times. Such studies generally last for years. Thus, longitudinal studies may not be the best choice when sources and financial support is limited and quick results are expected.

Experimental designs provide the researcher with the opportunity to determine the independent variable’s effect, to assign subjects to different groups, and to assess behaviors and responses.

Quasi-experimental designs involve similar processes to those of classical experimental design. The only distinction regards how participants are assigned to groups. Classical experimental design employs randomization to assign participants to
groups whereas quasi-experimental design makes use of non-randomized procedures.

Population can be defined as the group to be associated with the results that will be distilled after data analysis. Research studies contain two types of populations: target population and accessible population. Target population is the one that is almost impossible to reach out. On the other hand, accessible population is the realistic
choice of the researcher, and it is easily attainable.

All kinds of numerical values obtained via a method, technique, or instrument are accepted as data in quantitative research. Primary data collection techniques employed in quantitative research are tests and questionnaires.

Common descriptive analysis techniques often employed in quantitative research
include frequency, percentage, arithmetic mean, weighted mean, mode, median, range, and standard deviation. Inferential statistical techniques, on the other hand, are of two types: non-parametric statistical techniques and parametric statistical techniques. 

Qualitative research strives to build up a theory by investigating and understanding social phenomena in their natural environments. During a qualitative research process, researchers focus on people’s behaviors, actions, and interactions. Research process aims to comprehensively understand human behaviors in their natural environments, which requires the researcher be flexible, re-arrange the research
process in accordance with obtained data, adopt interpretive approach, and conduct data analysis through an inductive approach. 

Unlike quantitative approach, there is no need for hypotheses to develop research question(s) in a qualitative research study.

Action research is a cyclical and spiral process that is conducive to development and change, that encompasses individuals’ own practice, that entails systematic data collection, that enables reflective questioning, and as a result of these, that provides
opportunities to plan and apply new action.

Phenomenology is a qualitative research design focusing on perceptions and meanings that individuals develop based on their experiences. There are two primary approaches: descriptive and interpretive phenomenology. 

There are some principles that can guide researchers in analyzing research data,
reporting findings, and interpreting. These principles are 1) coding the data, 2) forming the themes, 3) arranging and identifying the data in accordance with codes and themes, and 4) reporting the findings.

Mixed method is a research approach where both quantitative and qualitative data sets are gathered and integrated so as to find answers to research questions.

Mixed method research questions could be developed via either method-centered or
content-centered approaches. But, the best mixed method research questions are those that reflect both the method and content. Such research questions are also known as hybrid mixed method research questions.

In the Exploratory Sequential Design, qualitative data is collected in the first stage
while quantitative data is gathered in the second because quantitative data is utilized to interpret qualitative findings.

The aim of this design is to examine the research problem within a social justice structure. Social justice structures that researchers enthusiastic to employ this design include feminist theory, critical race theory, queer theory, disability theory, or a
combination of these. The Social Justice Design aspires to transform lives of marginalized groups and disadvantageous individuals and to help them with the research results.