Psychometrics

Introduction

Psychology (from the Greek psyche, soul and logos, study) is a discipline that literally means science of the soul ».

It is conceptualized as the study of the behavior of individual organisms in interaction with their environment.

Contemporary psychology in the process of assimilating to the general status of the sciences, has been incorporating their methodology. Along with this, new methods of study and understanding of human behavior were appearing, which, supported by experimentation, gave rise among several options to one that is known by the name of method.

The psychometric method is understood as the set of procedures that lead to the quantitative assessment of psychological phenomena.

Psychometry

Psychometrics is a scientific discipline framed within the framework of the Behavioral Sciences Methodology and directly related to the field of psychological measurement.

At a practical level, psychometrics makes intensive use above all of statistical calculations and analysis to extract useful information from the repeated administration of the same test to a large group of people.

Psychometry is a branch of psychology and is a science whose purpose is to measure the psychological aspects of a person (human behavior), such as:

The first psychometric tests were built to measure intelligence.

Basically Psychometrics deals with theory and practice in the development, evaluation and application of measurement instruments within Psychology.

How are instruments constructed to measure psychological variables?

How is it determined if these instruments meet minimum quality requirements, so that they can be used as scientific instruments in psychological research?

How can these instruments be used to obtain measurements of the subjects in the variables of interest?

The field of psychometry is very broad, in educational settings tests are used to diagnose learning or behavior problems.

In the field of counseling, tests are used that measure occupational, social, academic, personality skills, interests, attitudes and values. They are also used in clinical and business counseling.

Psychometrics have been organized around three large blocks:

Theory of measurement, which would cover the theoretical foundation of measurement.

Scaling, which would cover the process of construction of measurement scales, that is, the methods for the construction of psychological and psychophysical scales.

Test Theory, which would include what is relative to how to evaluate these scales and how to use them to measure objects or subjects, that is, the logic and mathematical models underlying the construction and use of the tests.

Measurement theory

The measurement scales in psychology is to use mathematical procedures to assign numbers and identify physical and psychological attributes that make it possible to clarify individual differences.

A scale of measurement allows the investigator to determine the type of statistical analysis to use to examine a test and thus be able to consider the test as good.

The importance of measurement in psychology lies in its desire to scientifically establish the difference between psychological traits and states between individuals. For this, different scales are used to support the objective measurement of behavioral attributes.

Measurement and psychological theories. There are several theories that deal with why people behave the way they do. Some theorists focus the emphasis on heredity and the environment as shapers of human behavior.

Theories of types, of traits, psychoanalytic, phenomenological, are useful as a guide towards the measurement and understanding of personality.

Scaling

Scaling is the field of Psychometry whose fundamental objective is the construction of measurement scales and, therefore, includes all the necessary procedures for their elaboration.

Methods of elaboration of scales. It is defined as “elaboration of scales as the process of establishing rules for the numerical assignment in the measurement.

It is the process by which a measuring device is designed and calibrated, and the way in which numbers (or other indices), scale values are assigned to different quantities of the trait, attribute or characteristic being measured.

Methods of elaboration of scales. Usually there are different scalar measurement methods, which can be aimed at measuring people, stimuli and types of response. The scalar measurement of stimuli can be performed based on subjective estimates, since the evaluative task of the subject is required.

Discriminatory models are another option, these models emphasize the variability of the response to each stimulus.

Methods of elaboration of scales. In scalar measurement of subjects, the stimuli are constituted in samples which are presented to the subject to provide a type of response. There are three methods to measure response types, the most important are: judgments and feelings, comparative and absolute responses, response scale.

One-dimensional scaling methods. They allow ordering psychological objects (stimuli, subjects or responses) with respect to a single attribute. In these scaling methods, each of the objects to be scaled will receive a single value on the scale.

Multidimensional scales. The techniques of elaboration of multidimensional scales are used in large amounts of data in relatively few parameters ”. In this case, each object to be scaled will receive a scalar value for each dimension (or attribute) involved.

Test or Test

A test is an instrument whose purpose is to be an autonomous test and assessment criterion of a previously determined component of human behavior.

For this reason, for the test to enjoy this quality, it must meet some essential requirements:

Be standardized, that is, be objective (independent of who applies or interprets it).

Be consistent and reliable.

Have sensitivity to discriminate between different subjects, Have validity.

Reliability concept. A test is considered good when it has reliability, reliability refers to the consistency of the scores obtained by the same people when the same test or its equivalent is applied again.

A test lacks reliability when, in delayed applications made to the same subject, measurements with significant variation are obtained.

One factor that affects reliability is the length of the test. When the number of samples in the test is very extensive, its reliability can decrease. To determine the increase in the number of samples without altering the reliability there is a mathematical formula.

Validity concept. In the first place, it must be clear that you want to measure, since the validity of a test refers to the degree to which it measures what it is intended to measure.

The validity of a test is not stable so it will have to be reviewed periodically.

The validation of a Test (test) is the process of accumulation of tests and evidences "

In 1890 Mackeen Catell proposed the name of "mental tests" to date, these have given rise to various branches of knowledge and have been one of the most used instruments in research and application in the Sciences of man, counting when classifying them, five divisions among the most significant:

Development Test.

Inteligence test.

Specific Abilities Test.

Knowledge and Performance Test.

Personality test.

Psychological tests or tests are used to evaluate educational aspects, classification for example:

They are an important resource to test research hypotheses.

In the clinic it is a method to diagnose normal or pathological behavior, or establish a therapeutic treatment.