Unmatched count
Encyclopedia
In psychology
and social research
, unmatched count, or item count, is a technique to improve through anonymity
the number of true answers to possibly embarrassing or self-incriminating questions. It is very simple to use but yields only the number of people bearing the property of interest.
are divided into two groups at random
. One group (the control group
) is asked to answer a few harmless questions, while the other group gets one additional question (hence the name "unmatched count"), the one about the property of interest. The respondents are to reveal only the number of "yes"-answers they would have given. Since the interviewer does not know how they arrived at that number, it is safe to answer the awkward question truthfully. Due to the unmatched count of items, the number of people who answered "yes" to the awkward question can be mathematically deduced.
Let the number of "yes"-answers from this group be 31.
The second group additionally gets a question concerning the point of interest:
Let the number of "yes"-answers from this group be 34.
. Let the number of participants in each group be 50. 3 of them answered "yes" to the critical question, meaning that approximately 6% of the population have cheated on examinations.
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 research
Social research
Social research refers to research conducted by social scientists. Social research methods may be divided into two broad categories:* Quantitative designs approach social phenomena through quantifiable evidence, and often rely on statistical analysis of many cases to create valid and reliable...
, unmatched count, or item count, is a technique to improve through anonymity
Anonymity
Anonymity is derived from the Greek word ἀνωνυμία, anonymia, meaning "without a name" or "namelessness". In colloquial use, anonymity typically refers to the state of an individual's personal identity, or personally identifiable information, being publicly unknown.There are many reasons why a...
the number of true answers to possibly embarrassing or self-incriminating questions. It is very simple to use but yields only the number of people bearing the property of interest.
Method
The participants of the surveyStatistical survey
Survey methodology is the field that studies surveys, that is, the sample of individuals from a population with a view towards making statistical inferences about the population using the sample. Polls about public opinion, such as political beliefs, are reported in the news media in democracies....
are divided into two groups at random
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
. One group (the control group
Scientific control
Scientific control allows for comparisons of concepts. It is a part of the scientific method. Scientific control is often used in discussion of natural experiments. For instance, during drug testing, scientists will try to control two groups to keep them as identical and normal as possible, then...
) is asked to answer a few harmless questions, while the other group gets one additional question (hence the name "unmatched count"), the one about the property of interest. The respondents are to reveal only the number of "yes"-answers they would have given. Since the interviewer does not know how they arrived at that number, it is safe to answer the awkward question truthfully. Due to the unmatched count of items, the number of people who answered "yes" to the awkward question can be mathematically deduced.
Example
The control group is asked how many of the following statements apply:- I have moved house in the past.
- I own a pet.
- I like to go to the theatre.
- I have never been in a traffic accident.
Let the number of "yes"-answers from this group be 31.
The second group additionally gets a question concerning the point of interest:
- I have cheated on an examination.
Let the number of "yes"-answers from this group be 34.
Evaluation
The number of "yes"-answers in the control group is called the baseline. It is assumed that the second group would have given the same number, were it not for the critical question. Thus, their additional "yes"-answers (3 in the example) are due to the critical question. Their percentage is used to estimate the percentage of cheaters in the populationStatistical population
A statistical population is a set of entities concerning which statistical inferences are to be drawn, often based on a random sample taken from the population. For example, if we were interested in generalizations about crows, then we would describe the set of crows that is of interest...
. Let the number of participants in each group be 50. 3 of them answered "yes" to the critical question, meaning that approximately 6% of the population have cheated on examinations.
External links
- Joseph LaBrie, Mitchell Earleywine E. (2000). Sexual risk behavior and alcohol: Higher base rates revealed using the unmatched-count technique. The Journal of Sex Research, 37, 321–326
- T. Tsuchiya, Y. Hirai, S. Ono (2007). A study of the properties of the item count technique. Public Opinion Quarterly