MacArthur-Bates Child Development Index (CDI)

A series ofthree questionnaires that together span infancy through toddlerhood.  Thequestionnaires tap into the range of words that children know, as well as theirgrammatical skill.  The rating scale is designed to be completed by individualsvery familiar with children’s language skills, as they report on whether or notchildren know a variety of specific words (i.e., Vocabulary …

Lysosomes

Sometimes referred to as the ‘stomach of the cell’ (or a cell’s waste disposal system), these microscopic organelles are found in just about every eukaryotic cell.  They contain about 40 different types of hydrolase enzymes that not only break down waste material from carbohydrates, fats and proteins, but also clear out cellular debris (thus being …

Lumping (versus splitting)

The strategy of merging similar behavioral coding categories together into one superordinate code for subsequent analyses (lumping) as against creating new categories to classify samples (splitting).  Seemingly, the distinction was first expressed by Charles Darwin (1809-1882) in a letter to the botanist Joseph D. Hooker (1817-1911) in August, 1857.  Darwin wrote: “It is good to have …

Longitudinal studies

Ones that follow people over an extended period of time, usually several or more years, to examine patterns involving earlier and later experiences and development. The US is replete with such studies.    See Attrition, Autoregressive series/model, Cohort, Cohort effect, Compound symmetry, Cross-lagged correlation/regression model, Early Childhood Longitudinal Studies (ECLS), Follow-back design, Latent growth model, Linear …

Longitudinal-experimental studies

Studies of large samples followed over long periods of time, in which a preventive intervention is targeted to a randomly selected part of an ‘at-risk’ group.  The relative benefits and drawbacks should be compared to those carried out using the microgenetic method.   See ‘At-risk’ concept, Auto-regressive models, Follow-back design, Growth models, Longitudinal design, Longitudinal …

Longitudinal design

A study that takes place over time, preferably with at least three time points so that change both between and within individuals can be charted.  See Auto-regressive models, Cohort, Cohort effect, Cross-lagged correlation/regression model, Cross-sectional design, Developmental research, Follow-bacjk design, Latent growth model, Longitudinal-experimental studies, Longitudinal studies, Microgenetic method, Multiple cohort study, Panel studies, Prodiction …

Logographic writing systems

A system of writing in which the printed symbols represent entire words without relating to pronunciation.  The main  contemporary example of this system is Chinese whose characters, or logograms, are used with various degrees of modifications in Japanese, Korean and Vietnamese and a number of other East Asian languages.  Ancient Egyptian hieroglyphics and the writing …