A term used in describing the progress of an epidemic for the time following the latent period and during which a patient infected with the disease is able to discharge infectious matter in some way and possibly communicate the disease to other susceptibles.

A form of multidimensional scaling applicable to data consisting of a number of proximity matrices from different sources, i.e. different subjects. The method allows for individual differences in the perception of the stimuli by deriving weights for each subject that can be used to stretch or shrink the dimensions of the recovered geometrical solution.

The process of adjusting a crude mortality or morbidity rate for one or more variables by using a known reference population.

An estimation method used in the fitting of structural equation models. Ordinary least squares is first used to estimate the reduced form parameters. Using the relations between structural and reduced form parameters it is subsequently solved for the structural parameters in terms of the estimated reduced form parameters. Indirect least squares estimates are consistent but […]

Synonym for binary variable. Also used for a manifest variable that is thought to be related to an underlying latent variable in the context of structural equation models.

A plot of some diagnostic quantity obtained after the fitting of some model, for example, Cook’s distances, against the corresponding observation number. Particularly suited to the detection of outliers.

A measure of the magnitude of a variable at one point (in time, for example), to its value at another. An example is the consumer price index. The main application of such numbers is in economics.

The time elapsing between the receipt of infection and the appearance of symptoms. The length of the incubation period depends on the disease, ranging from days in, for example, malaria, to years in something like AIDS. Estimation of the incubation period is important in investigations of how a disease may spread and in the projection […]

A problem that sometimes arises when the number of parameters increases in tandem with the number of observations. For example, models for panel studies may include individual-specific fixed intercepts, called “incidental parameters”, in addition to the “structural parameters” of interest, making the number of parameters tend to infinity as the number of individuals tends to […]

A measure of the rate at which people without a disease develop the disease during a specific period of time.