Empirical Method

The empirical method is generally taken to mean the approach of using a collection of data to base a theory or derive a conclusion in science. The word empirical denotes information gained by means of observation or experiments. Empirical data is data produced by an experiment or observation.

Description

"Empirical" in science can be synonymous with "experimental." In this sense, an empirical result is an experimental observation. In this context, the term semi-empirical is used for qualifying theoretical methods which use in part basic axioms or postulated scientific laws and experimental results. Such methods are opposed to theoretical ab initio methods which are purely deductive and based on first principles. The empirical method is not sharply defined and is often contrasted with the precision of the experimental method, where data are derived from the systematic manipulation of variables in an experiment. Some of the difficulty in discussing the empirical method is from the ambiguity of the meaning of its linguist root: empiric.

A central concept in modern science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses. It is usually differentiated from the philosophic usage of empiricism by the use of the adjective empirical or the adverb empirically. The term refers to the use of working hypotheses that are testable using observation or experiment. In this sense of the word, scientific statements are subject to, and derived from, our experiences or observations. The standard positivist view of empirically acquired information has been that observation, experience, and experiment serve as neutral arbiters between competing theories.

However, since the 1960s, Thomas Kuhn has promoted the concept that these methods are influenced by prior beliefs and experiences. Consequently it cannot be expected that two scientists when observing, experiencing, or experimenting on the same event will make the same theory-neutral observations. The role of observation as a theory-neutral arbiter may not be possible. Theory-dependence of observation means that, even if there were agreed methods of inference and interpretation, scientists may still disagree on the nature of empirical data.

Empirical research

Empirical research is a way of gaining knowledge by means of direct observation or experience. Empirical evidence (the record of one's direct observations or experiences) can be analyzed quantitatively or qualitatively. Through quantifying the evidence or making sense of it in qualitative form, a researcher can answer empirical questions, which should be clearly defined and answerable with the evidence collected (usually called data). Research design varies by field and by the question being investigated. Many researchers combine qualitative and quantitative forms of analysis to better answer questions which cannot be studied in laboratory settings, particularly in the social sciences and in education.

In some fields, quantitative research may begin with a research question (e.g., "Does listening to vocal music during learning a word list have an effect on later memory for these words?") which is tested through experimentation in a lab. Usually, a researcher has a certain theory regarding the topic under investigation. Based on this theory some statements, or hypotheses, will be proposed (e.g., "Listening to vocal music has a negative effect on learning a word list."). From these hypotheses predictions about specific events are derived (e.g., "People who study a word list while listening to vocal music will remember fewer words on a later memory test than people who study a word list in silence."). These predictions can then be tested with a suitable experiment. Depending on the outcomes of the experiment, the theory on which the hypotheses and predictions were based will be supported or not.

The term empirical was originally used to refer to certain ancient Greek practitioners of medicine who rejected adherence to the dogmatic doctrines of the day, preferring instead to rely on the observation of phenomena as perceived in experience. Later empiricism referred to a theory of knowledge in philosophy which adheres to the principle that knowledge arises from experience and evidence gathered specifically using the senses. In scientific use the term empirical refers to the gathering of data using only evidence that is observable by the senses or in some cases using calibrated scientific instruments. What early philosophers described as empiricist and empirical research have in common is the dependence on observable data to formulate and test theories and come to conclusions.

Usage

The researchers attempts to describe accurately the interaction between the instrument (or the human senses) and the entity being observed. If instrumentation is involved, the researcher is expected to calibrate his/her instrument by applying it to known standard objects and documenting the results before applying it to unknown objects. In other words, it describes the research that has not been taken place before and their results.

In practice, the accumulation of evidence for or against any particular theory involves planned research designs for the collection of empirical data, and academic rigor plays a large part of judging the merits of research design. Several typographies for such designs have been suggested, one of the most popular of which comes from Campbell and Stanley (1963). They are responsible for popularizing the widely cited distinction among pre-experimental, experimental, and quasi-experimental designs and are staunch advocates of the central role of randomized experiments in educational research.

Scientific research

Accurate analysis of data using standardized statistical methods in scientific studies is critical to determining the validity of empirical research. Statistical formulas such as regression, uncertainty coefficient, t-test, chi square, and various types of ANOVA (analyses of variance) are fundamental to forming logical, valid conclusions. If empirical data reach significance under the appropriate statistical formula, the research hypothesis is supported. If not, the null hypothesis is supported (or, more correctly, not rejected), meaning no effect of the independent variable(s) was observed on the dependent variable(s).

It is important to understand that the outcome of empirical research using statistical hypothesis testing is never proof. It can only support a hypothesis, reject it, or do neither. These methods yield only probabilities.
Among scientific researchers, empirical evidence (as distinct from empirical research) refers to objective evidence that appears the same regardless of the observer. For example, a thermometer will not display different temperatures for each individual who observes it. Temperature, as measured by an accurate, well calibrated thermometer, is empirical evidence. By contrast, non-empirical evidence is subjective, depending on the observer. Following the previous example, observer A might truthfully report that a room is warm, while observer B might truthfully report that the same room is cool, though both observe the same reading on the thermometer. The use of empirical evidence negates this effect of personal (i.e., subjective) experience. Empirical research can yield empirical evidence, which can then be analyzed for statistical significance or reported in its raw form.

Empirical cycle

  • Observation: The collecting and organisation of empirical facts; Forming hypothesis.
  • Induction: Formulating hypothesis.
  • Deduction: Deducting consequenses of hypothesis as testable predictions.
  • Testing: Testing the hypothesis with new empirical material.
  • Evaluation: Evaluating the outcome of testing.

Other details

In statistics, "empirical" quantities are those computed from observed values, as opposed to derived from theoretical considerations. In economics, "empirical" generally refers to statistical or econometric analysis of numeric data. Other forms of observation-based hypothesis testing[clarification needed] are not considered to be "empirics." The use of the adjective empirical, especially in scientific studies using statistics, may also indicate that a particular correlation between two parameters has been found, but that so far, no theory for the mechanism of the connection is known.

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