Discuss how the measurements derived from questionnaires differ from measures used in the pure sciences. Do these differences

Discuss how the measurements derived from questionnaires differ from measures used in the pure sciences. Do these differences undermine psychology’s claim to be a science?

Questionnaires have become a popular measure of all kinds of phenomena; social attitudes, personality, and employment. They have come along way since the early theoretical work of Catell, and Spearman. However they are not without their critics and many have argued against the validity questionnaires cast doubt on the scientific validity. (Michell, 2000). It is measurement in psychology that will be the focus of this essay and the scientific validity of the measurements used in psychology.

Eysenck (1986) stated that if psychology is to ‘prosper’ it has to follow the scientific method that is used in the physical science, which is hypothetico-deductive method (Eysenck, 1986). To connect theory to real world observations the hypothetico-deductive method is used in both psychology and pure science. It is the primary method of scientific enquiry in the natural sciences and psychology (Whewell, 1866.)The method is usually as follows; the researcher formulates a testable hypothesis, this is then either accepted or falsified on the results of the test/experiment (Popper 1959). The point is that theories that are tested repeatedly and survive without being falsified are confirmed, until if ever, the time they do not hold up to tests (Whewell, 1866; Popper, 1959). It is easy to see natural physical phenomena as quantitative amenable to measurement, for instance, length measured with the standardized measurement unit, meter. Measurements enable scientists to make statements about quantities of an object with a view to developing a theory about the object and its properties and behavior.psychology also a range of methods from brain imaging techniques, to recording reaction times, to the using questionnaires to measure intelligence. (Haig & Borsboom, 2008). The discussion will now turn to the issue of measurement in psychology. In order to do this a brief description of the use of measurement in the pure sciences and an introduction to the world of psychometrics will be presented.

Unfortunately measurement is not quite as straightforward as in the physical sciences. Measurement works with quantities and it is this that presents the challenges for psychology. Psychology has unobservable mental phenomena that are not observable intelligence, personality, mood is how to quantify the unobservable and what measurements would be appropriate? Indeed it has been an issue of much controversy in the area of quantitative psychology (Michell, 1997). Cronbach (1990) refers to psychometrics, ‘Psychometric testing sums up performance in numbers. Its ideal is expressed in two famous old pronouncements: If a thing exists, it exists in some amount, and, if it exists in some amount, it can be measured” Cronbach, 1990

The foundations of quantitative psychology were based largely on work and theories from psychophysics. Dating back to1888, Fechner linked, theoretically quantitative psychology to quantitative physics, via his psychophysical law, he supplemented his law with a range of measurement methods (Michell, 1997, 2000). Fechner posited these measurements as being the same as those in physics. Fechner believed that reality is and experience is quantitative, ‘both the physical and mental realms, in common, were subordinate, he believed, ‘‘to the principle of mathematical determination’’ (Fechner, 1887, in Michell, 1997). In this way Fechner really introduced the quantitative approach in psychology. Psychologists, following Fechner’s lead then began ‘constructing number-generating procedures which, they thought, measured psychological attributes’, (Michell, 1997)

Spearman inspired by Fechner put forward a quantitative theory in an attempt to explain intellectual performance and individual differences in on test performance of intelligence. He tested this theory by presenting problem solving tests he thought represented intelligence. Michell (1997) pointed out that ‘these were to do with the number of abilities involved in solving tasks of specific kinds and were not sensitive to the issue of whether or not the postulated abilities were quantitative in structure’. Like Fechner, Spearman adopted the belief that psychological attributes had to be quantitative and the primary problem was to develop procedures and instruments for their measurement. The acceptance of psychological attributes was accepted by psychologists in the fervent belief that the discipline should aspire to be a science as any other. This is known as the scientific or quantitative imperative, (Michell, 1990, 1997)

Spearman (1904, 1923) in his investigations of intelligence also devised a statistical technique called factor analysis. This technique is used in psychometrics and reduces variability among variables down to lower factors (variables). Using factor analysis Spearman discovered a general (g) factor of human intelligence (1904). This general factor ‘g’ brings together cognitive test scores across a range of questions (seemingly unrelated), as representing one underlying construct or factor. is a construct that is responsible for individuals performance on tests of intelligence tests. As Michell points out however variations and individual differences in performance on these tests are not just due to intelligence but could involve factors such as motivation (Kline, 1998).

Spearman’s work outlined above assumes the quantifiable nature of psychology and adhered to the view of Stevens, originally a psychophysicist, turned his attention to quantitative psychology. He made the now well known statement, ‘measurement, is defined as the assignment of numerals to objects or events according to rules’, (Stevens 1946). This view, that psychological attributes are quantifiable by being represented by numerical values, was widely accepted by psychologist and according to Michell, 1997 it ‘blinded the majority of psychologists to the scientific necessity of testing via experiment that psychological attributes are quantitative was dramatically revealed over the subsequent four decades’. (Michell, 1997).

How do researchers know what they are measuring is ‘real’ and if the tool they are using is measuring the phenomena at all? Mental life and human behavior are complex but one can see that the use of well tested, reliable scales and questionnaires have aided psychologists understanding of human behavior. People such as Spearman (1923) and Cattell’s (1943, 1990) many measures of personality, intelligence and motivation have contributed a great deal to the study of psychology, (Kline, 1998). Researche rshought that personality can be seen as having an underlying construct that gives rise to the patterns and consistence of behaviors , feelings and thoughts over time and across varying situations. Personality is something that is unique to each of us but it is a dynamic complex interplay of underlying constructs or traits, probably with a biological origins and neurobiological correlates that are common to many people across time, (Kline, 2000). Psychologists now widely use psychometric tools including questionnaires (responses on a number of items) to measure hypothesised psychological attributes such as intelligence, personality traits and social attitudes (Michell, 2000). Undoubtedly scientific psychology has made some important contributions to describing mental life and behavior in humans, and with the emergence of more seemingly scientific imaging methods researchers are discovering more and more about the human mind.

Researchers such as Joel Michell (1997, 2000) has been scathing of what he sees as the failure of psychologists to ‘make any serious attempts within psychometrics’ to address the fundamental question of whether psychological attributes such as above, are quantitative and as such do psychometric measures have any construct validity (Kline, 1998). The hypothesis upon which it is premised, that psychological attributes are quantitative For Michell it is this false assumption that underlies the fallacy in viewing psychometrics and psychology as a science. He, and others (Haig & Borsboom, 1998; Barrett, 2002) goes further to say there has been very little attention paid to the actual evidence for that premise and that has been hugely detrimental to the study of psychology. Michelle suggests (2000, 2001) that ideological and economic concerns which have benefited from presenting psychology as a quantitative science. For example the abundant use of questionnaires in education and mental health services is testament to their economic value.

The idea that the act of measuring can change that which is measured, is worthy of discussion in psychological research, and is also an issue in the pure sciences (Kline, 1998). For example, a participant may want respond differently depending on their experience of questionnaire, motivations for taking part in the study and the presence or absence of the researcher. Even what the researcher decides to research is not objective but in line with the current scientific paradigms and theories (Russell, 1938), and economic and social norms.

In conclusion it can be said that questionnaires and psychometrics are not of same as science, more efforts need to be made in psychology to understand the fundamental concepts of measurement in psychology. However, perhaps the future of psychology lies in conceiving new techniques that are suitable just for psychological science rather than following slavishly the doctrines of the natural sciences Psychology is legitimate in its own right. Perhaps as some have thought there will always be aspects of psychology those are non-quantifiable. Perhaps as, back as far as 1990, Aiken and colleagues stated that there is not enough emphasis on concepts underlying measurement in psychology in the education of psychology students. Perhaps as some have thought there will always be aspects of psychology that are non-quantifiable. As Paul Kline (1998) stated ‘it may be that some psychological variables are measurable and others are not.’

‘The psychometric tradition has been good at classification but weak at understanding, explanation, or description of the phenomena that most interest psychologists’ (Michell, 1990). Hopefully psychology will now turn its attention to inwards rather than aspiring to the other sciences.

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