Census is data collected from every member in the society by governments for official purposes and could vary from general demographic information such as sex, age, education, place of birth to questions about households. If the entire population is surveyed, meaning it is a census representing 100% the population.

Quantitative research, or also called scientific research method, is a way of obtaining information that provides the researcher with accurate and reliable data that is numeric in nature and has been obtained through testing or comparing ideas in the public arena.

Quantitative research, as part of empirical research, enables to describe populations and phenomena in a detailed tradition based on figures or data, and enables the political scientist to make propositions out of relationships between two or more variables. Observation and experimentation are the strategies that can be employed to test an assumption or a theory. Observation is the most used strategy by political scientists for international relations, or other social sciences while experimentation is not that commonly used due to its nature of testing.

As its meaning may indicate, descriptive studies are about describing a particular situation or case as detailed and elaborated as possible, and it enables the classification and organization of taxonomic categories as in survey methods.

Population or sample, which can also be called as the unit of analysis, define the group that your research will be about. The more descriptive information you provide about the sample, the more likely it will represent the population investigated. Therefore, decisions about the sample is counted as one of the most important steps in the research process.

Associational research enables for understanding or identification of relations between certain variables.

Correlational studies enable the researcher to identify how one or a set of variables are related to another or enable the researcher to make predictions. Especially in the case where it is difficult to conduct an experimental study, the researcher can make use of the available data to analyze the relationships among different variables.

Correlational research contradicts with experimental research in the sense that no variable is manipulated in this method. Thus, it is important to say that correlation should not be confused with causal relation, it only provides an existing or nonexisting relationship between variables.

Causal comparative research which is also called as ex post facto (after the fact for Latin) attempts to determine the cause or consequences of differences that already exist between identified set of subjects.

It is a research type that explicitly attempts to influence a particular variable. Second, it is considered to be the best method to test hypothesis related to cause-and-effect relationships.

There is an increasing interest in utilizing survey research in the field of political sciences as it provides opportunities to build theory through empirical data via understanding the attitudes, behavior, and dynamics in the society.

Empirical research is about any research that is based on observational data indicating that knowledge is derived from actual experience or experiment rather than from a certain theory or belief.

Cross-sectional research, which means collecting data through a survey across a pretermined population at one point in time. Thus, the survey is administered to a representative sample at the same time.

The national time series surveys generally are data collected over the years that are in the interest of political scientists. Indicators may vary from economic to social indicators, such as income levels, education level, employment or unemployment figures by education level, in or out migration trends within a nation.

Election data provide opportunity to analyze voting behavior of individuals through combining this with ecological and contextual data to produce maps and graphs of political tendencies that explain individual behavior across geographical area and specific contexts.

Political sciences, or international relations fields value policy decisions and the changing trends of individuals based on policy making decisions or applications, therefore through a panel study, the researcher can collect data from similar samples at different times.

• Coverage error, which refers to drawing samples form a list of irrelevant samples to represent the population.
• Sampling error, which exists any time when the researcher reaches some of the sample and not all members. 
• Nonresponse error, which occurs when some particular units of analysis tend to answer some particular items which are likely to influence the estimate of the findings.
• Measurement error is described as the difference between the estimate produced and the true value in case the respondents may answer inaccurately to the survey questions.

Regardless if the researcher is aiming at doing descriptive research or correlational research, there are some basics of doing scientific research, which relates to asking for research questions or stating
hypothesis if the design selected requires one. Next, it is also important to make sure that the data collected and analyzed is scientifically valid
and reliable.

Research questions should be feasible, clear, significant, specific, ethical and measurable to initiate a research study.

A variable is a concept that may refer to any variation in a context such as artifacts used in elections.

‘Random sampling’ is a strategy that enables every member in the population to become selected and be a part of the study. Random sampling is essential as it avoids the likelihood to select a biased sample.

Validity refers to the correctness, appropriateness, meaningfulness, and
usefulness of the data collected or the relevancy of the data collection instrument.