Psychometrics Chapter 3 (100% Verified Solutions)

variability correct answers key building block of psychological measurement; the degree of differences within a set of test scores or among the values of a psychological attribute; differences among the scores within a distribution; aimed to be quantified, via variance or standard deviation; individual differences is at the heart of research and the application of research in the behavioural sciences; psychometric concepts (e.g. reliability, validity) are dependent on the ability to quantify the differences among people co-variability correct answers key building block of psychological measurement; the degree to which the variability in one set of scores corresponds with variability in another set of scores; degree to which 2 variables are associated with each other psychological measurement correct answers rests on the implicit (how a single person differs from the public) or explicit (psychological differences among people) assumption that people differ with respect to their behaviour or other psychological characteristics; rests on the concept of variability; based on the simple assumption that psychological differences exist and can be detected with well-designed measurement processes inter-indidivdual differences correct answers exist between people; psychometric concepts (e.g. reliability, validity) are dependent on the ability to quantify the differences among people intra-individual differences correct answers emerge in one person over time or under different circumstances; psychometric concepts (e.g. reliability, validity) are dependent on the ability to quantify the differences among people individual differences correct answers what any domain of psychology (experimental/non-experimental, basic/applied) is dependent on; process of quantification of psychological differences begins with the recognition that scores on a psychological test will/can vary from person to person or from time to time distribution correct answers tested group's set of scores; when taken from a group of people, or from one person at different points in time, test scores yield a distribution of scores; many fundamental concepts in psychological measurement are built on the way we detect and describe distributions of test scores histogram correct answers scores (e.g. age, IQ) on the x-axis and frequency of people with the scores on the y-axis scatterplot correct answers a graphical description of a correlation; provides a quick indication of the direction and magnitude of a relationship variance correct answers index of variability; quantifies variability or individual differences in a distribution or set of scores; reflects variability as the degree to which the scores in a distribution deviate from the mean of the distribution; mean of squared deviation scores; sum of the squared deviations about the mean divided by N - 1; Σ(x - x̄)2/(N), where x̄ = ΣX/N and x = each