A type of factor analysis where the specific number of factors and the pattern of the zero and non-zero loadings are hypothesized a priori and in advance of the estimation. CFA is often used to compare one specific alternative factor model hypothesis to another. See Exploratory factor analysis (EFA), Factor analysis, Factor loadings, Five Factor …
Author Archives: Brian Hopkins
Confound
Means literally ‘to throw something into disorder’. In a research context, this term is used when there are two or more explanations for a significant result, usually because a study cannot control one or more extraneous variables. See Causal pathway, Confounding variable, Contamination, Experimental method
Configural perception
Assignmentof the spatial relationships between facial features during face processing. Face processing involves not only configural or holistic processing(perceiving the combination of the different parts of a face into a gestalt),but also featural processing. The latter involves sensitivityto first-order relational configuration such that two eyes are above thenose and this is above the mouth to second-order relations resulting fromthe …
Conduct disorder
A psychiatric diagnosis, created by the American Psychiatric Association, for children who violate age-appropriate social norms and rules, especially by physically aggressing persons, damaging property, stealing, running away from home, and not going to school. Thus, it is a consistent pattern of socially non-acceptable, norm-breaking behavior leading to functional disability. Conduct disorder has been associated …
Cones and rods
Two classes of photoreceptors in the retina. In total, there are over 125 million of such receptors in the retina, with the rods being more numerous at some 120 million than the cones at around 6 to 7 million (see first figure below). Both of these photosensitive membranes have distinctive shapes, both are stacked in …
Concept
An abstract idea inferred or derived from particular instances (e.g., cognition, temperament). Concepts can also represent physical objects such as a table and chair as well as their relationships. They serve to relate facts to theories and propositions, and in this way can become variables. A concept, however, is more encompassing than a variable. So, …
Conditional knockouts
Usually transgenic animals in which specific genes can be knocked out (or deleted) only in certain cells or at certain times under experimental control in an attempt to identify what effect that gene has in the life of the organism. The mouse is unique among mammals with regard to the degree to which its genome …
Computational models
Computer programs that are used to explain different aspects of cognitive and behavioral development and processing (e.g., balance scale task). A computational model implements a theory of development and can be used to test this theory and to generate predictions that can be tested empirically. Undoubtedly, one of the founders of computational modelling was Alan …
Composite (or sum) scale
A scale giving a score created by aggregating several of the items in a questionnaire or set of tests (e.g., sub-scales of an IQ test). An important psychometric consideration in the derivation of multi-item composite scales concerns their internal consistency. See Construct, Cronbach’s alpha, Internal consistency
Compound symmetry
Constant variances and constant covariances of the dependent measure across the levels of a factor in analysis of variance (i.e., the variances and covariances are equal between pairs of variables, but not necessarily between variances and covariances). This property of the variance-covariance matrix is present when the main diagonal elements of a set of multivariate …