The multiple site entry technique is a strategy that can be used in online research (also called Internet-based research or Web-based research) to target different samples via different recruitment sites and compare their data. It is a method used in

behavioral Behavior (American English) or behaviour (British English) is the range of actions of individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as well as the inanimate p ...

and

social research Social research is research conducted by social scientists following a systematic plan. Social research methodologies can be classified as quantitative and qualitative. * Quantitative designs approach social phenomena through quantifiable ...

to assess the presence and impact of self-selection effects. Self-selection effects can be considered a major challenge in social science research. With the invention of online research in the 1990s the multiple site entry technique became possible, because the recruitment of participants via different links (

URL A uniform resource locator (URL), colloquially known as an address on the Web, is a reference to a resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identi ...

s) is very easy to implement. It can be assumed that there is no

self-selection bias In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling. It is commonly used to describe situations where the characteristics of the peo ...

if the data sets coming from different recruitment sites do not differ systematically.

Method

Several links to the study are placed on different

website A website (also written as a web site) is any web page whose content is identified by a common domain name and is published on at least one web server. Websites are typically dedicated to a particular topic or purpose, such as news, educatio ...

s, in Internet forums,

social media platforms Social media are interactive technologies that facilitate the creation, sharing and aggregation of content (such as ideas, interests, and other forms of expression) amongst virtual communities and networks. Common features include: * Online ...

, or offline media that are likely to attract different types of participants, or are mailed out to different

mailing list A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. Mailing lists are often rented or sold. If rented, the renter agrees to use the mailing list only at contra ...

s. In order to identify the recruitment sources, the published

s contain source identifying information and the

HTTP protocol HTTP (Hypertext Transfer Protocol) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, wher ...

is analyzed by different referrer information. This means, a unique string of characters is appended to the

for each recruitment source, e.g. “...index.html?source=studentlist” for a list of students. The

data file A data file is a computer file which stores data to be used by a computer application or system, including input and output data. A data file usually does not contain instructions or code to be executed (that is, a computer program). Most of th ...

will have a column („source“) containing an entry of the referring source for each participant (“studentlist“). The collected

data set A data set (or dataset) is a collection of data. In the case of tabular data, a data set corresponds to one or more table (database), database tables, where every column (database), column of a table represents a particular Variable (computer sci ...

s can then be compared for differences in results, and also for differences in relative degree of appeal (measured via dropout),

demographic data Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration. Demographic analysis examine ...

, central results, and

data quality Data quality refers to the state of qualitative or quantitative pieces of information. There are many definitions of data quality, but data is generally considered high quality if it is "fit for tsintended uses in operations, decision making and ...

The figure illustrates the multiple site entry technique.

Impact

Several studies have shown that the multiple site entry technique is a useful tool to determine the presence and impact of

self-selection In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling. It is commonly used to describe situations where the characteristics of the pe ...

in online research (also called Internet-based research, Web-based research). The multiple site entry technique helps to detect potential sampling problems, which in turn ensures the

quality Quality may refer to: Concepts *Quality (business), the ''non-inferiority'' or ''superiority'' of something *Quality (philosophy), an attribute or a property *Quality (physics), in response theory *Energy quality, used in various science discipli ...

and generalizability in the data

collection Collection or Collections may refer to: Computing * Collection (abstract data type), the abstract concept of collections in computer science * Collection (linking), the act of linkage editing in computing * Garbage collection (computing), autom ...

over the Internet. Moreover, this technique can be applied to different kinds of Internet-based studies, e.g. trauma surveys.

Fields of Application

The multiple site entry technique has already been applied successfully in different research areas. For instance, Holbrook and Lavrakas discussed the multiple site entry technique in the field of experimental survey research. Moreover, it can also be used in a broader research context, e.g., in

sex research Sexology is the scientific study of human sexuality, including human sexual interests, behaviors, and functions. The term ''sexology'' does not generally refer to the non-scientific study of sexuality, such as social criticism. Sexologists app ...

and in

health science The following outline is provided as an overview of and topical guide to health sciences: Health sciences – those sciences that focus on health, or health care, as core parts of their subject matter. Health sciences relate to multiple ...

References

{{reflist Social science methodology