Experimental techniques
Encyclopedia
Experimental research designs are used for the controlled testing of causal
processes.
The general procedure is one or more independent variables are manipulated to determine their effect on a dependent variable. These designs can be used where:
The most common applications of these designs in marketing research
and experimental economics
are test markets and purchase labs. The techniques are commonly used in other social sciences including sociology
, psychology
, and social work
.
, intervening, and antecedent variable
s. In the most basic model, cause (X) leads to effect (Y). But there could be a third variable (Z) that influences (Y), and X might not be the true cause at all. Z is said to be a spurious variable and must be controlled for. The same is true for intervening variable
s (a variable in between the supposed cause (X) and the effect (Y)), and anteceding variables (a variable prior to the supposed cause (X) that is the true cause). When a third variable is involved and has not been controlled for, the relation is said to be a zero order relationship. In most practical applications of experimental research designs there are several causes (X1, X2, X3). In most designs, only one of these causes is manipulated at a time.
in a simulated store. Researchers modify one variable at a time (for example; price, packaging, shelf location, size, or competitors’ offerings) and determine what effect that has on sales volume. Internet-based purchase labs (called virtual purchase labs) are becoming more common.
Simplified versions of the purchase laboratory are often used for pragmatic reasons. An example of this would be to use tachistoscope
s for testing packaging and shelf location.
is an example of this. A new product is typically introduced in a select number of cities. These cities must be representative of the overall national (or international) population. They should also be relatively unpolluted by outside influences (for example : media from other cities). The marketer has some control over the marketing mix
variables, but almost no control over the broader business environment variables
. Competitors could change their prices
during the test. Government could change the level of taxes. New competing products
could be introduced. An advertising campaign
could be initiated by competitors. Any of these spurious variables could contaminate the test market.
Causality
Causality is the relationship between an event and a second event , where the second event is understood as a consequence of the first....
processes.
The general procedure is one or more independent variables are manipulated to determine their effect on a dependent variable. These designs can be used where:
- There is time priority in a causal relationship (cause precedes effect),
- There is consistency in a causal relationship (a cause will always lead to the same effect), and
- The magnitude of the correlation is great.
The most common applications of these designs in marketing research
Marketing research
Marketing research is "the function that links the consumer, customer, and public to the marketer through information — information used to identify and define marketing opportunities and problems; generate, refine, and evaluate marketing actions; monitor marketing performance; and improve...
and experimental economics
Experimental economics
Experimental economics is the application of experimental methods to study economic questions. Data collected in experiments are used to estimate effect size, test the validity of economic theories, and illuminate market mechanisms. Economic experiments usually use cash to motivate subjects, in...
are test markets and purchase labs. The techniques are commonly used in other social sciences including sociology
Sociology
Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...
, psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
, and social work
Social work
Social Work is a professional and academic discipline that seeks to improve the quality of life and wellbeing of an individual, group, or community by intervening through research, policy, community organizing, direct practice, and teaching on behalf of those afflicted with poverty or any real or...
.
Controls
One of the most important requirements of experimental research designs is the necessity of eliminating the effects of spuriousSpurious relationship
In statistics, a spurious relationship is a mathematical relationship in which two events or variables have no direct causal connection, yet it may be wrongly inferred that they do, due to either coincidence or the presence of a certain third, unseen factor In statistics, a spurious relationship...
, intervening, and antecedent variable
Antecedent variable
In statistics and social sciences, an antecedent variable is a variable that can help to explain the apparent relationship between other variables that are nominally in a cause and effect relationship...
s. In the most basic model, cause (X) leads to effect (Y). But there could be a third variable (Z) that influences (Y), and X might not be the true cause at all. Z is said to be a spurious variable and must be controlled for. The same is true for intervening variable
Intervening variable
An intervening variable is a hypothetical internal state that is used to explain relationships between observed variables, such as independent and dependent variables, in empirical research.- History :...
s (a variable in between the supposed cause (X) and the effect (Y)), and anteceding variables (a variable prior to the supposed cause (X) that is the true cause). When a third variable is involved and has not been controlled for, the relation is said to be a zero order relationship. In most practical applications of experimental research designs there are several causes (X1, X2, X3). In most designs, only one of these causes is manipulated at a time.
Purchase laboratory
A true experimental design requires an artificial environment to control for all spurious, intervening, and antecedent variables. A purchase laboratory approaches this ideal. Participants are given money, script, or credit to purchase productsProduct (business)
In general, the product is defined as a "thing produced by labor or effort" or the "result of an act or a process", and stems from the verb produce, from the Latin prōdūce ' lead or bring forth'. Since 1575, the word "product" has referred to anything produced...
in a simulated store. Researchers modify one variable at a time (for example; price, packaging, shelf location, size, or competitors’ offerings) and determine what effect that has on sales volume. Internet-based purchase labs (called virtual purchase labs) are becoming more common.
Simplified versions of the purchase laboratory are often used for pragmatic reasons. An example of this would be to use tachistoscope
Tachistoscope
A tachistoscope is a device that displays an image for a specific amount of time. It can be used to increase recognition speed, to show something too fast to be consciously recognized, or to test which elements of an image are memorable. Actual tachistoscopes use a slide or transparency projector...
s for testing packaging and shelf location.
Online settings
The internet provides opportunities for experimental design on a large scale. It is possible to manipulate different variables, while holding everything else constant. This design is appropriate for between-subject experimentation. Most professional email vendors offer this opportunity or experimental design in emails. Several companies offer software for experimental design on websites.Test markets
Quasi-experimental designs control some, but not all, of the extraneous factors. A test marketTest market
A test market, in the field of business and marketing, is a geographic region or demographic group used to gauge the viability of a product or service in the mass market prior to a wide scale roll-out...
is an example of this. A new product is typically introduced in a select number of cities. These cities must be representative of the overall national (or international) population. They should also be relatively unpolluted by outside influences (for example : media from other cities). The marketer has some control over the marketing mix
Marketing mix
The term "marketing mix" was coined in 1953 by Neil Borden in his American Marketing Association presidential address. However, this was actually a reformulation of an earlier idea by his associate, James Culliton, who in 1948 described the role of the marketing manager as a "mixer of ingredients",...
variables, but almost no control over the broader business environment variables
Environmental scanning
Environmental scanning is one component of the global environmental analysis. Environmental monitoring, environmental forecasting and environmental assessment complete the global environmental analysis. Environmental scanning refers to the macro environment.The global environment refers to the...
. Competitors could change their prices
Pricing
Pricing is the process of determining what a company will receive in exchange for its products. Pricing factors are manufacturing cost, market place, competition, market condition, and quality of product. Pricing is also a key variable in microeconomic price allocation theory. Pricing is a...
during the test. Government could change the level of taxes. New competing products
New product development
In business and engineering, new product development is the term used to describe the complete process of bringing a new product to market. A product is a set of benefits offered for exchange and can be tangible or intangible...
could be introduced. An advertising campaign
Advertising
Advertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...
could be initiated by competitors. Any of these spurious variables could contaminate the test market.
Experimental research designs
In an attempt to control for extraneous factors, several experimental research designs have been developed, including:- Classical pretest-post test - The total population of participants is randomly divided into two samples; the control sample, and the experimental sample. Only the experimental sample is exposed to the manipulated variable. The researcher compares the pretest results with the post test results for both samples. Any divergence between the two samples is assumed to be a result of the experiment.
- Solomon four group design - The sample is randomly divided into four groups. Two of the groups are experimental samples. Two groups experience no experimental manipulation of variables. Two groups receive a pretest and a post test. Two groups receive only a post test. This is an improvement over the classical design because it controls for the effect of the pretest.
- Factorial designFactorial experimentIn statistics, a full factorial experiment is an experiment whose design consists of two or more factors, each with discrete possible values or "levels", and whose experimental units take on all possible combinations of these levels across all such factors. A full factorial design may also be...
- this is similar to a classical design except additional samples are used. Each group is exposed to a different experimental manipulation.
See also
- Choice ModellingChoice ModellingChoice modelling attempts to model the decision process of an individual or segment in a particular context. Choice modelling may also be used to estimate non-market environmental benefits and costs....
- MarketingMarketingMarketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...
- Marketing researchMarketing researchMarketing research is "the function that links the consumer, customer, and public to the marketer through information — information used to identify and define marketing opportunities and problems; generate, refine, and evaluate marketing actions; monitor marketing performance; and improve...
- Design of experimentsDesign of experimentsIn general usage, design of experiments or experimental design is the design of any information-gathering exercises where variation is present, whether under the full control of the experimenter or not. However, in statistics, these terms are usually used for controlled experiments...
- Experimental economicsExperimental economicsExperimental economics is the application of experimental methods to study economic questions. Data collected in experiments are used to estimate effect size, test the validity of economic theories, and illuminate market mechanisms. Economic experiments usually use cash to motivate subjects, in...
Lists of related topics
- List of statistics topics
- List of marketing topics
- List of management topics
- List of economics topics
- List of finance topics
- List of accounting topics
Further reading
- Box, G. E. P., & Draper, N. R. (1987). Empirical model-building and response surfaces. New York: Wiley.
- Box, G. E. P., Hunter, W. G., & Hunter, S. J. (1978). Statistics for experimenters: An introduction to design, data analysis, and model building. New York: Wiley.
- Mason, R. L., Gunst, R. F., & Hess, J. L. (1989). Statistical design and analysis of experiments with applications to engineering and science. New York: Wiley.
- Taguchi, G. (1987). Jikken keikakuho (3rd ed., Vol I & II). Tokyo: Maruzen. English translation edited by D. Clausing. System of experimental design. New York: UNIPUB/Kraus International.