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Comments on the Comments on the Testing and Testing and Measurement ExhibitionMeasurement Exhibition

Jacques Grégoire Jacques Grégoire Université de Louvain, BelgiumUniversité de Louvain, Belgium

Why is there a need for such an Why is there a need for such an exhibition ?exhibition ?

Psychological measurement is part of our Psychological measurement is part of our life (school, hospital, job...) and can have a life (school, hospital, job...) and can have a strong impact on our destiny.strong impact on our destiny.

Public misunderstanding of psychological Public misunderstanding of psychological measures.measures.

Even professionals have often little Even professionals have often little understanding of the psychological understanding of the psychological measures.measures.

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Why is there a need for such an Why is there a need for such an exhibition ?exhibition ?

Several authors (e.g. Meranda, 2003) complained Several authors (e.g. Meranda, 2003) complained that programs to educate and train that programs to educate and train psychometricians are on steady decline.psychometricians are on steady decline.

A complete understanding of the technical A complete understanding of the technical sections of psychological test manuals is sections of psychological test manuals is notnot accessible to a large number of test users. accessible to a large number of test users.

Many users do not have the conceptual Many users do not have the conceptual knowledge to judge the quality of a test.knowledge to judge the quality of a test.

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Why is there a need for such an Why is there a need for such an exhibition ?exhibition ?

Clients do not understand:Clients do not understand: Specificity of psychological measures,Specificity of psychological measures, Norms related measures,Norms related measures, Validity of the scores has always to be appraise Validity of the scores has always to be appraise

according to the context of test use,according to the context of test use, Error of measurement,Error of measurement, Probabilistic nature of psychological measurement… Probabilistic nature of psychological measurement…

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Which measurement topic is the Which measurement topic is the most difficult to explain to the public?most difficult to explain to the public?

The specificity of psychological The specificity of psychological measures: measures: We are measuring latent variables through We are measuring latent variables through

observable indicators,observable indicators, The scales we use have arbitrary zero => The scales we use have arbitrary zero =>

relative measures; only comparisons between relative measures; only comparisons between individuals, relative to time (Flynn effect) and individuals, relative to time (Flynn effect) and culture.culture.

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Which measurement topic is the Which measurement topic is the most difficult to explain to the public?most difficult to explain to the public?

Prior knowledge on objective variables Prior knowledge on objective variables having a non-arbitrary zero (e.g. having a non-arbitrary zero (e.g. height) create an obstacle:height) create an obstacle: Observed indicators are mistaken for latent Observed indicators are mistaken for latent

variablesvariables Ordinal or interval scales are used as ratio scaleOrdinal or interval scales are used as ratio scale

Measures are considered as absoluteMeasures are considered as absolute Inappropriate comparisons Inappropriate comparisons

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How can we attract the public to the How can we attract the public to the exhibition?exhibition?

Suggested title (more provocative):Suggested title (more provocative): ““Measuring the mind”Measuring the mind” ““Measuring humans”Measuring humans”

Measuring psychological characteristics Measuring psychological characteristics having a rather high emotional intensity: e.g. having a rather high emotional intensity: e.g. intelligence, personality, memory…intelligence, personality, memory…

Then explaining the true meaning of these Then explaining the true meaning of these measures.measures.

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