Quantitative Research

Quantitative research
In the social sciences, quantitative research refers to the systematic empirical investigation of quantitative properties and phenomena and their relationships. The objective of quantitative research is to develop and employ mathematical models, theories and/or hypotheses pertaining to phenomena. The process of measurement is central to quantitative research because it provides the fundamental connection between empirical observation and mathematical expression of quantitative relationships.
Quantitative research is used widely in social sciences such as sociology, anthropology, and political science. Research in mathematical sciences such as physics is also 'quantitative' by definition, though this use of the term differs in context. In the social sciences, the term relates to empirical methods, originating in both philosophical positivism and the history of statistics, which contrast qualitative research methods.
Overview
Quantitative research is generally made using scientific methods, which can include:
· The generation of models, theories and hypotheses
· The development of instruments and methods for measurement
· Experimental control and manipulation of variables
· Collection of empirical data
· Modeling and analysis of data
· Evaluation of results
In the social sciences particularly, quantitative research is often contrasted with qualitative research which is the examination, analysis and interpretation of observations for the purpose of discovering underlying meanings and patterns of relationships, including classifications of types of phenomena and entities, in a manner that does not involve mathematical models. Approaches to quantitative psychology were first modelled on quantitative approaches in the physical sciences by Gustav Fechner in his work on psychophysics, which built on the work of Ernst Heinrich Weber. Although a distinction is commonly drawn between qualitative and quantitative aspects of scientific investigation, it has been argued that the two go hand in hand. For example, based on analysis of the history of science, Kuhn (1961, p. 162) concludes that “large amounts of qualitative work have usually been prerequisite to fruitful quantification in the physical sciences”[1]. Qualitative research is often used to gain a general sense of phenomena and to form theories that can be tested using further quantitative research. For instance, in the social sciences qualitative research methods are often used to gain better understanding of such things as intentionality (from the speech response of the researchee) and meaning (why did this person/group say something and what did it mean to them?)(Kieron Yeoman).
Although quantitative investigation of the world has existed since people first began to record events or objects that had been counted, the modern idea of quantitative processes have their roots in Auguste Comte's positivist framework.
[edit] Statistics in quantitative research
Statistics is the most widely used branch of mathematics in quantitative research outside of the physical sciences, and also finds applications within the physical sciences, such as in statistical mechanics. Statistical methods are used extensively within fields such as economics, social sciences and biology. Quantitative research using statistical methods starts with the collection of data, based on the hypothesis or theory. Usually a big sample of data is collected - this would require verification, validation and recording before the analysis can take place. Software packages such as SPSS and R are typically used for this purpose. Causal relationships are studied by manipulating factors thought to influence the phenomena of interest while controlling other variables relevant to the experimental outcomes. In the field of health, for example, researchers might measure and study the relationship between dietary intake and measurable physiological effects such as weight loss, controlling for other key variables such as exercise. Quantitatively based opinion surveys are widely used in the media, with statistics such as the proportion of respondents in favor of a position commonly reported. In opinion surveys, respondents are asked a set of structured questions and their responses are tabulated. In the field of climate science, researchers compile and compare statistics such as temperature or atmospheric concentrations of carbon dioxide.
Empirical relationships and associations are also frequently studied by using some form of General linear model, non-linear model, or by using factor analysis. A fundamental principle in quantitative research is that correlation does not imply causation. This principle follows from the fact that it is always possible a spurious relationship exists for variables between which covariance is found in some degree. Associations may be examined between any combination of continuous and categorical variables using methods of statistics.
[edit] Measurement in quantitative research
Views regarding the role of measurement in quantitative research are somewhat divergent. Measurement is often regarded as being only a means by which observations are expressed numerically in order to investigate causal relations or associations. However, it has been argued that measurement often plays a more important role in quantitative research. For example, Kuhn argued that within quantitative research, the results that are shown can prove to be strange. This is because accepting a theory based on results of quantitative data could prove to be a natural phenomenon. He argued that such abnormalities are interesting when done during the process of obtaining data, as seen below:
When measurement the parts from theory, it is likely to yield mere numbers, and their very neutrality makes them particularly sterile as a source of remedial suggestions. But numbers register the departure from theory with an authority and finesse that no qualitative technique can duplicate, and that departure is often enough to start a search (Kuhn, 1961, p. 180).
In classical physics, the theory and definitions which underpin measurement are generally deterministic in nature. In contrast, probabilistic measurement models known as the Rasch model and Item response theory models are generally employed in the social sciences. Psychometrics is the field of study concerned with the theory and technique for measuring social and psychological attributes and phenomena. This field is central to much quantitative research that is undertaken within the social sciences.
Quantitative research may involve the use of proxies as stand-ins for other quantities that cannot be directly measured. Tree-ring width, for example, is considered a reliable proxy of ambient environmental conditions such as the warmth of growing seasons or amount of rainfall. Although scientists cannot directly measure the temperature of past years, tree-ring width and other climate proxies have been used to provide a semi-quantitative record of average temperature in the Northern Hemisphere back to 1000 A.D. When used in this way, the proxy record (tree ring width, say) only reconstructs a certain amount of the variance of the original record. The proxy may be calibrated (for example, during the period of the instrumental record) to determine how much variation is captured, including whether both short and long term variation is revealed. In the case of tree-ring width, different species in different places may show more or less sensitivity to, say, rainfall or temperature: when reconstructing a temperature record there is considerable skill in selecting proxies that are well correlated with the desired variable.
[edit] Quantitative methods
Quantitative methods are research techniques that are used to gather quantitative data - information dealing with numbers and anything that is measurable. Statistics, tables and graphs, are often used to present the results of these methods. They are therefore to be distinguished from qualitative methods.
In most physical and biological sciences, the use of either quantitative or qualitative methods is uncontroversial, and each is used when appropriate. In the social sciences, particularly in sociology, social anthropology and psychology, the use of one or other type of method has become a matter of controversy and even ideology, with particular schools of thought within each discipline favouring one type of method and pouring scorn on to the other. Advocates of quantitative methods argue that only by using such methods can the social sciences become truly scientific; advocates of qualitative methods argue that quantitative methods tend to obscure the reality of the social phenomena under study because they underestimate or neglect the non-measurable factors, which may be the most important. The modern tendency (and in reality the majority tendency throughout the history of social science) is to use eclectic approaches. Quantitative methods might be used with a global qualitative frame. Qualitative methods might be used to understand the meaning of the numbers produced by quantitative methods. Using quantitative methods, it is possible to give precise and testable expression to qualitative ideas. This combination of quantitative and qualitative data gathering is often referred to as mixed-methods research.
[edit] Examples of quantitative research
Research that consists of the percentage amounts of all the elements that make up Earth's atmosphere.
Survey that concludes that the average patient has to wait two hours in the waiting room of a certain doctor before being selected.
An experiment in which group x was given two tablets of Aspirin a day and Group y was given two tablets of a placebo a day where each participant is randomly assigned to one or other of the groups.
The numerical factors such as two tablets, percent of elements and the time of waiting make the situations and results quantitative.

Quantitative Research Methods
Description
Use quantitative research methods in market research when:
· You want to know “how many” and/or “how often”
· You want to profile a target audience by determining what proportion of the audience has certain behaviors, behavioral intentions, attitudes, and knowledge related to the health concern, and whether specific determinants predict behaviors at a statistically significant level.
You conduct quantitative market research generally involves:
· Surveying a large group of people (usually several hundred), and
· Using a structured questionnaire that contains predominantly closed-ended, or forced-choice, questions.
To design and conduct a quantitative survey, you should consider getting input from a survey expert. Together you will need to consider issues related to designing an appropriate sample, using valid and reliable measures, and conducting a pretest before the survey study is launched. Most surveys are custom studies designed to answer a specific set of research questions. Some surveys are omnibus studies, in which you add questions about your topic to an existing survey.
Surveys can be conducted face-to-face, by mail or telephone, or by computer. They can be self-administered or administered by an interviewer. Tools such as computer-assisted telephone interviewing or touch-screen surveys via a Web site can be useful.
Pros
· When the survey involves a convenience sample (e.g., a mall intercept study), data can be collected and analyzed fairly quickly
· When the survey involves a statistically valid random sample, the results from the sample can be generalized to the entire population if the response rate is high enough
· Surveys can provide reliable (i.e., repeatable) direction for planning programs and messages
· Surveys can be anonymous, which is useful for sensitive topics
· Like qualitative research methods, surveys can include visual material and can be used to pretest prototypes
· You can generalize your findings beyond your participant group.
Cons
· They have a limited ability to probe answers
· People who are willing to respond may share characteristics that don’t apply to the audience as a whole, creating a potential bias in the study
· They can be very costly.
Common Uses
· Assess the proportion of your target audience within a community
· Assess the proportion of a target audience that practices a behavior
· Assess the proportion of a target audience that recalls a message.
Resources
To compare qualitative and quantitative methods, see the Qualitative/Quantitative Comparison Chart.
Scroll to your method of interest in the Tools for Research.