Lee Joseph Cronbach: biography of this psychologist

It is difficult, or even impossible, to carry out research in Psychology without the influence of Lee Cronbach.

He is an essential author to understand Psychology as it is today, and without a doubt one of the most influential academics of the last century.

The numerous contributions of him to the knowledge of science have a transversal character, since he dedicated himself to epistemological reflection and to the definition of a method with which to enhance the rigor of the scientific findings that could be derived from this discipline.

• Related article: "History of Psychology: main authors and theories"

Biography of Lee Joseph Cronbach

In the successive lines we will delve into the life of the author through a short biography of Lee Joseph Cronbach, although stopping in what were some of his contributions of greater depth of him.

Academic trajectory

Lee Joseph Cronbach was a psychologist of American origin who made numerous contributions to the field of psychometry and education, among the that highlights the Cronbach alpha index (widely used today in order to determine the reliability of an evaluation tool quantitative).

Lee Cronbach was born in the city of Fresno in 1916, and there he would obtain his university degree (Bachelor of Arts, 1934), subsequently pursuing his Master's degree at Berkeley and his Ph.D. in Chicago (Educational Psychology, 1937). Along the path of him, He showed interest in the methodological rigor of the studies that were published from the framework of Psychology, so he proposed important tools to strengthen it.

As a teacher he gave training in many universities in his country; especially in those of Chicago, Illinois and Stanford (where he remained a great part of his life as an academic). In recognition of his extensive input, Lee Cronbach was named president of the American Psychological Association (APA) in 1957. and from one of its divisions (Evaluation and Measurement), as well as from the American Association for Educational Research itself in 1964.

In addition to his contribution to psychological evaluation, he did extensive work in the field of instruction. During the 70s had the opportunity to be director of the Stanford Evaluation Consortium; an organization directed to research and training that depended on the departments of Psychology and that he designed extensive projects to improve coordination between the educational centers of the districts that make up the State of California.

Cronbach's research was also relevant in the clinical and community settings. He developed programs for health and child and juvenile delinquency, emphasizing an extraordinary rigor in his work and making visible the importance of social and political reality in their planning and development. With these contributions he substantially improved the way in which research was carried out in the social, health and educational fields.

Lee Cronbach died in 2001 from a congestive heart disease, leaving for posterity an enduring intellectual legacy for Psychometry, Educational Psychology and Epistemology. Not surprisingly, he is one of the authors with the highest number of references in scientific articles from around the world.

Theoretical and epistemological principles

The variety of studies in which the author's work is used exemplifies very well one of the postulates on which he would base himself, which is none other than the existence of two Independent but firmly related psychologies: an experimental type (which requires manipulation in the laboratory to observe causes / consequences with absolute control of the situation) and another correlational (through which one could observe the way in which two variables interact with each other in environments of lower restriction).

Lee Cronbach's View on Psychology he aspired to the formulation of essential laws that could become widely applicable and generalization, in a way similar to what happens with physics or chemistry. He considered that it was possible to reel off the associations that occur in human phenomena in order to establish a posteriori relationships of a causal type that, even based on the laws of probability, would bring its object of study closer to the positivist rigor of other disciplines.

Thus, he understood the behavior and thought of the human being as realities imbued in nature, and therefore subject to the same explanatory principles that the natural sciences possess. These sought to establish certain regularities between the study phenomena, with a special sensitivity to the probability of error which is inherent to its complexity, but elaborating universal principles on which to sustain a body of useful and reproducible.

Lee Cronbach was able to recognize that the purpose of psychology should not be limited to the experimental reproduction of laboratory conditions to test assumptions of nomothetic nature (applicable to all subjects in their character of particles extracted from a group), but had to contemplate the phenomena that were displayed in the environments everyday. In this sense, aspired to the unification of the two Psychologies that he himself distinguished, in an attempt at syncretism that would turn out to be paradigmatic.

Lee Cronbach's reflections on this question led him to affirm that the reduction of psychic phenomena that occurs in situations experimentalists could not give a precise answer to the problems of the human being, whose life is debated in the permanent course of interactions with multiplicity of variables, among which the basic sociocultural coordinates and the substratum of the scenario in which its day to day.

In conclusion, he would point out that the observation of phenomena (with a mind devoid of prejudices and open to fascination) is key to establish a knowledge of sufficient entity to equate it to that of Physics or Chemistry. Regarding the latter, I would recall that they are not free from uncertainty either, since the macro and microphysical world assumes a virtually infinite number of variables for its formulations).

Contributions as a methodologist

Lee Cronbach's vision on Psychology was a historic milestone, showing the desire to positivist comparison with other sciences from a perspective that embraced reason and circumvented all naivety. However, the contribution for which he continues to be a so remembered author today was his famous Cronbach's alpha, a measure inserted within the G Theory (or Theory of Generalizability) with which the Classical Theory of Tests was expanded.

The Classical Theory of the Tests contemplates that any score (empirical value) that a subject obtains in tests designed to measure a construct psychological score is made up of its real score plus the random error (this being the difference observed when subtracting the empirical score and the real). This error can occur as a result of methodological deficiencies, or even circumstances such as the place where the measurement is carried out or the personal situation of the appraiser.

Theory G would be complementary to the Classical Theory of Tests. It would be intended to quantify the reliability of a test through the determination of all sources of error, guaranteeing a more precise decision-making process. And it is that this process occupied a notable part of the academic life of the author, for which he suggested methods directly from statistics.

In this context, Cronbach's alpha would rise as one of the statistics designed to assess the internal consistency or reliability of a measurement tool (or the factors that compose it). Although the concept was introduced by Cyril J. Hoyt (a professor in the Department of Educational Psychology at the University of Minnesota) and Louis Guttman (a mathematician and sociologist at the Hebrew University of Jerusalem) some years earlier; it was Cronbach who was finally able to popularize it, reformulate it, and extend it to the scientific community to a greater extent.

Every time a researcher tries to measure an attribute, he has to consider the fact that this is never directly quantifiableRather, its assessment must be carried out through a process of abstraction that conforms to the theoretical model from which it comes. The common thing is that it ends up being carried out by administering a questionnaire, whose items are subsumed as second-order factors (depression or anxiety, for example).

To evaluate the way in which the measurement is accurate and explores with a minimum margin of error what it actually claims to measure, Cronbach's alpha is used. Is about the weighted mean of the variances or correlations between the items that make up the factor, obtaining from its use a score that oscillates between 0 and 1 (0.70 being the cut-off point from which the The test can be regarded as reliable and used for assessment purposes in any field of the Psychology).

• You may be interested: "Cronbach's alpha (α): what is it and how is it used in statistics"

An evaluation at the service of society

Psychological evaluation, for Cronbach, was indivisibly linked to social policies, and should be subject to the needs of the people in their aspiration to achieve a state of justice and plurality. He understood that although political influences were unavoidable, it was necessary for an adaptation process to take place between these and social programs that will be based on sensitivity to needs through a flexible approach to the object of study.

Due to this vision he postulated an evaluative planning that could accommodate the enormous diversity at that each potential investigation was subject, in which two stages were included: the convergent and the divergent. In the first, the possible variables that could be explored were extracted, while in the second, a hierarchy of priorities for the study was established.

Finally, the same author considered that the interpretation of results was a second stage in their evaluation, in which some of the information could be lost due to the subjectivity of the evaluator. That is why he considered structured training essential to select appropriate questions and direct the process to action, that is, towards decision-making in which the improvement of the lives of people or institutions is prioritized evaluated.

Bibliographic references:

• Cronbach, L. (1951). Alpha coefficient and internal structure of the tests. Psychometrika, 16 (3), 297-334
• Cronbach, L. and Meehl, P. (1955). Construct validity in psychological tests. Psychological Bulletin, 52, 281-302.
• Cronbach, L. (1957). The two disciplines of scientific psychology. American Psychologist, 12, 671-684.