Introduction

Psychometrics refers to the field of psychology and education that is devoted to testing, measurement, assessment and related activities. It is concerned with the objective measurement of scales and knowledge abilities, attitudes, personality traits, and educational achievement. It is also concerned with statistical research bearing on measurement theory for example interclass correlation.

The main types of tests include:

♧ Intelligence tests which assesses intelligence capabilities of an individual.

♧ Aptitude tests.

♧ Achievement tests which assesses the degree and achievement.

♧ Creativity tests which assesses capacity of novelty.

♧ Personality tests which assesses traits.

♧ Interest inventories which assesses preference for activities.

♧ Behavioral activities which measures behaviors and their antecedents or consequences.

♧ Neuropsychological tests which measure cognitive, sensory, and perceptual or mortar functions.

The ten most commonly used tests include:

♧ Wechsler intelligence scale for children (WISC).

♧ Bender Visual- mortar Gestalt technique.

♧ Wechsler adult intelligence scale (WAIS).

♧ Minnesota Multiphasic Personality Invention.

♧ Rorcharch Ink Blot test.

♧ Thematic Apperception Test (TAT).

♧ Sentence Completion.

♧ Good Enough Draw- a Person Test.

♧ House- Tree Person Test.

♧ Stanford- Binet Intelligence Scale.

History of Psychometrics

According to Boake (2002) test assessing cognitive and perceptual abilities had been developed well before then. The first wide spread use of psychological and educational assessment occurred in China more than 3000 years ago. Measures of problem solving, visual spatial perception, divergent thinking and creativity wee used.

Charles Darwin is the inspiration behind Sir Francis Galton who led to the creation to the creation of psychometrics. In 1859, Darwin published his book The Origin of Species which pertained to individual differences in animals. The book discussed how individual members in a species differ and how they posses characteristics that are more adaptive and successful or less or less adaptive and less successful. The adaptive and successful survive and give way to the next generation, who would just as or more adaptive and successful. This idea, previously studied in animals, led to Galton’s interest and study of human beings and how they differ from one another and also how to measure these differences.

Galton wrote a book entitled Hereditary Genius. The book discussed about the characteristics that people posses and how those characteristics make them ‘fit’ than others. Most of the early theoretical and applied work in psychometrics was undertaken in an attempt to measure intelligence. Galton, who is considered the father of psychometrics, devised and included mental tests among his anthropometric measures.

Psychometrics in the 19th century

There is little known fact that psychometrics as a science began in Cambridge between 1886 and 1889. The first lab dedicated to the subject was set up within the Cavendish Physics laboratory in the University of Cambridge by Jams Mc Keen Cattell in 1889. In 1889, Cattell returned from England to a Psychology professor at the University of Pennsylvania, where he had established a laboratory of Psychology. Largely ignoring the bodily measurements that had dominated Galton’s program, he measured his student’s hand strength, rate of movement, pain threshold, reaction times, judgment of elapsed time etc. , referring to this as ‘mental tests’ and expecting them to be related to other evidence of mental ability. He moved to Columbia University in 1891, where he was permitted by the University administration to record for all freshman entering students, the results from his mental testing program. He promoted his mental testing program, but without setting forth either a theoretical or operational justification for it.

Psychometrics in the 20th century

1901: Clark Wissler (Cattell’s student) did the first basic validation research examining the relation between the old ‘mental tests’ scores and academic achievement.

Wissler found out that, for each Cattell’s ‘mental tests’ the correlations with class grades were essentially zero (Wissler 1901). Those findings effectively terminated the testing of sensory reactions and motor skills for assessing mental vision and tactile sensitivity continues to be recognized.

1905: Alfred Binnet and Simon in France published an intelligence scale developed for use with Paris School children that served as a model of intelligence tests in North America and Europe and following WWI. Binnet and Simon introduced the concept of mental age determined by earning a test score that is characteristic of children of a given chronological age, and they developed a test suitable for estimating a child’s mental age.

The intelligence test movement was given a boost by the work of Charles Spearman in Great Britain, who analyzed results from the battery of cognitive results and interrupted the analysis as providing support for a general intelligence factor.

1906: Henry H. Goddard became the research director at Vineland (NS) Training School for feeble-minded. He provided a translation of the first session of the Binnet- Simon scale.

1917: American Psychological Association (APA) came up with a plan to offer assistance in connection with psychological problems arising from the military emergency. This plan was approved in August 1917 by the secretary of war.

In the USA, group tests of mental abilities during WW1 were helpful in selecting soldiers such measures were found to be psychologically sound and led way towards individual intelligence scales which advanced in statistical analysis and understanding of results.

1930s: Intelligence testing saw a period of aggressive growth; its entry into the USA for WW1 saw intelligence testing utilized for assigning recruits. The Wechsler-Bellevue was developed where technical advances at the time allowed for more sophisticated statistical analyses that soon made it a dominant adult individual intelligence scale. The Wechsler-Bellevue intelligence scale represented a particular approach to cognitive assessment between 1880s and WW1.

♤ Contribution of Wechsler

1). A variety of technical innovation such as Standard Deviation scores.

2). Combining verbal and performance tests into a single scale. These are just a few of Wechsler-Bellevue scale features that have been replicated by intelligence test developed later.

Also in the 1930s the thematic apperception was invented, it was a well-known projective measure.

1940s: The Minnesota Multiphasic Personality Inventory was developed. It is one of the most recognized personality self-reposts. It is was developed to serve as an aid in assessing adult patients during routine psychiatric care and to determine severity of symptoms as well as an estimate of change.

1970s: In the early 1970s Theodore Millon developed multiple scales to measure dimensions of personality and assist with the diagnostic process. Just with cognitive measures, the era of WW2 contributed to the increased use of personality and emotional functioning tests as well.

The emergence of such measures helped define and expand the role of psychological evaluation in the mental health field but some led the way in terms of computerized assessment.