Personality testing

A personality test is a method of assessing human personality constructs. Most personality assessment instruments (despite being loosely referred to as 'personality tests') are in fact introspective (i.e., subjective) self-report questionnaire (Q-data, in terms of LOTS data) measures or reports from life records (L-data) such as rating scales. Attempts to construct actual performance tests of personality have been very limited even though Raymond Cattell with his colleague Frank Warburton compiled a list of over 2000 separate objective tests that could be used in constructing objective personality tests. One exception however, was the Objective-Analytic Test Battery, a performance test designed to quantitatively measure 10 factor-analytically discerned personality trait dimensions. A major problem with both L-data and Q-data methods is that because of item transparency, rating scales and self-report questionnaires are highly susceptible to motivational and response distortion ranging all the way from lack of adequate self-insight (or biased perceptions of others) to downright dissimulation (faking good/faking bad) depending on the reason/motivation for the assessment being undertaken. A personality test is a method of assessing human personality constructs. Most personality assessment instruments (despite being loosely referred to as 'personality tests') are in fact introspective (i.e., subjective) self-report questionnaire (Q-data, in terms of LOTS data) measures or reports from life records (L-data) such as rating scales. Attempts to construct actual performance tests of personality have been very limited even though Raymond Cattell with his colleague Frank Warburton compiled a list of over 2000 separate objective tests that could be used in constructing objective personality tests. One exception however, was the Objective-Analytic Test Battery, a performance test designed to quantitatively measure 10 factor-analytically discerned personality trait dimensions. A major problem with both L-data and Q-data methods is that because of item transparency, rating scales and self-report questionnaires are highly susceptible to motivational and response distortion ranging all the way from lack of adequate self-insight (or biased perceptions of others) to downright dissimulation (faking good/faking bad) depending on the reason/motivation for the assessment being undertaken. The first personality assessment measures were developed in the 1920s and were intended to ease the process of personnel selection, particularly in the armed forces. Since these early efforts, a wide variety of personality scales and questionnaires have been developed, including the Minnesota Multiphasic Personality Inventory (MMPI), the Sixteen Personality Factor Questionnaire (16PF), the Comrey Personality Scales (CPS), among many others. Although popular especially among personnel consultants, the Myers–Briggs Type Indicator (MBTI) has numerous psychometric deficiencies. More recently, a number of instruments based on the Five Factor Model of personality have been constructed such as the Revised NEO Personality Inventory. However, the Big Five and related Five Factor Model have been challenged for accounting for less than two-thirds of the known trait variance in the normal personality sphere alone. Estimates of how much the personality assessment industry in the US is worth range anywhere from $2 and $4 billion a year (as of 2013). Personality assessment is used in wide a range of contexts, including individual and relationship counseling, clinical psychology, forensic psychology, school psychology, career counseling, employment testing, occupational health and safety and customer relationship management. The origins of personality assessment date back to the 18th and 19th centuries, when personality was assessed through phrenology, the measurement of bumps on the human skull, and physiognomy, which assessed personality based on a person's outer appearances. Sir Francis Galton took another approach to assessing personality late in the 19th century. Based on the lexical hypothesis, Galton estimated the number of adjectives that described personality in the English dictionary Galton's list was eventually refined by Louis Leon Thurstone to 60 words that were commonly used for describing personality at the time. Through factor analyzing responses from 1300 participants, Thurstone was able to reduce this severely restricted pool of 60 adjectives into seven common factors. This procedure of factor analyzing common adjectives was later utilized by Raymond Cattell (7th most highly cited psychologist of the 20th Century—based on the peer-reviewed journal literature), who subsequently utilized a data set of over 4000 affect terms from the English dictionary that eventually resulted in construction of the Sixteen Personality Factor Questionnaire (16PF) which also measured up to eight second-stratum personality factors. Of the many introspective (ie. subjective) self-report instruments constructed to measure the putative Big Five personality dimensions, perhaps the most popular has been the Revised NEO Personality Inventory (NEO-PI-R) However, the psychometric properties of the NEO-PI-R (including its factor analytic/construct validity) has been severely criticized. Another early personality instrument was the Woodworth Personal Data Sheet, a self-report inventory developed for World War I and used for the psychiatric screening of new draftees. There are many different types of personality assessment measures. The self-report inventory involves administration of many items requiring respondents to introspectively assess their own personality characteristics. This is highly subjective, and because of item transparency, such Q-data measures are highly susceptible to motivational and response distortion. Respondents are required to indicate their level of agreement with each item using a Likert scale or, more accurately, a Likert-type scale. An item on a personality questionnaire, for example, might ask respondents to rate the degree to which they agree with the statement 'I talk to a lot of different people at parties' on a scale from 1 ('strongly disagree') to 5 ('strongly agree'). Historically, the most widely used multidimensional personality instrument is the Minnesota Multiphasic Personality Inventory (MMPI), a psychopathology instrument originally designed to assess archaic psychiatric nosology. In addition to subjective/introspective self-report inventories, there are several other methods for assessing human personality, including observational measures, ratings of others, projective tests (e.g., the TAT and Ink Blots), and actual objective performance tests (T-data). The meaning of personality test scores are difficult to interpret in a direct sense. For this reason substantial effort is made by producers of personality tests to produce norms to provide a comparative basis for interpreting a respondent's test scores. Common formats for these norms include percentile ranks, z scores, sten scores, and other forms of standardised scores.