Models of Psychometrics and SamplingAs the science of test theory and testing, psychometrics has two models, each of which is supported by a different set of assumptions. Based on a researcher's goals

Trait Test Design PSY3700 Multimedia Assessment and Psychometrics ©20 16 South University 2 Trait Test Design The Two Models of Psychometrics Latent trait models are used to make estimations about knowledge, ability, or the strength of a trait as demonstrated by an individual through performance on a designated test. Underlying assumptions that support this model of psychometrics are that latent traits are expressed through test items, that a latent trait is unidimensional, and that all test items on the test measure this trait. Critics of this model p oint out that not all items taken from a psychological test effectively measure the latent trait and that when many psychological tests are considered, the assumption of unidimensionality is violated (Cohen & Swerdlik, 2002). In making decisions in the rea l world, people often use mental shortcuts to size up a person according to the presumed traits. Thus, it may be impossible to eliminate latent trait designs altogether because they emulate, albeit more objectively, everyday judgments made about others bas ed on their presumed traits (Rust & Golombok, 2009). Standardized tests of intelligence have traditionally reflected the use of the trait design and have been criticized for not mapping onto the real world. For example, is intelligence best represented by one's full - scale intelligence quotient (IQ) score across subtests that measure verbal and nonverbal skills?

Alternatively, is intelligence best reflected in one's ability to show adaptive behaviors when presented with a challenging scenario? Because the de bate continues to wage over the use of the two models to accurately tap the essence of intelligence, it is likely that these questions will remain unanswered. PSY3700 Multimedia Assessment and Psychometrics ©20 16 South University 3 Trait Test Design The Two Models of Psychometrics References Cohen, R., & Swerdlik, M. (2002). Psychological testing and assessment: An introduc tion to test and measurement (5th ed.). Boston, MA: McGraw -Hill. Rust, J., & Golombok, S. (2009). Modern psychometrics: The science of psychological assessment (3rd ed.). New York, NY: Taylor & Francis. © 201 6 South University