Categorical Data: Categorical data are reflecting the classification of objects into different categories. For example, people who receive a mail order offer might be classified as "no response," "purchase and pay," "purchase but return the product," and "purchase and neither pay nor return." Browse Other Glossary Entries
View Full DescriptionCohort study: A cohort study is a longitudinal study that identifies a group of subjects sharing some attributes (a "cohort") then takes measurements on the subjects at various points in time and records data for the group. A cohort study is often used to compare two groups over time, e.g....
View Full DescriptionCross sectional study: Cross sectional studies are those that record data from a sample of subjects at a given point in time. See also cross sectional data , longitudinal study . Browse Other Glossary Entries
View Full DescriptionCross-sectional Analysis: Cross-sectional analysis is concerned with statistical inference from cross-sectional data . Browse Other Glossary Entries
View Full DescriptionCross-sectional Data: Cross-sectional data refer to observations of many different individuals (subjects, objects) at a given time, each observation belonging to a different individual. A simple example of cross-sectional data is the gross annual income for each of 1000 randomly chosen households in New York City for the year 2000....
View Full DescriptionCohort data: Cohort data records multiple observations over time for a set of individuals or units tied together by some event (say, born in the same year). See also longitudinal data and panel data. Browse Other Glossary Entries
View Full DescriptionCrossover Design: In randomized trials, a crossover design is one in which each subject receives each treatment, in succession. For example, subject 1 first receives treatment A, then treatment B, then treatment C. Subject 2 might receive treatment B, then treatment A, then treatment C. A crossover design has the...
View Full DescriptionDisproportionate stratified random sampling: See Stratified Sampling (method ii). Browse Other Glossary Entries
View Full DescriptionEffect: In design of experiments, the effect of a factor is an additive term of the model, reflecting the contribution of the factor to the response. See Variables (in design of experiments) for an explanatory example. Browse Other Glossary Entries
View Full DescriptionEffect Size: In a study or experiment with two groups (usually control and treatment), the investigator typically has in mind the magnitude of the difference between the two groups that he or she wants to be able to detect in a hypothesis test. This magnitude, e.g. a 20% improvement in...
View Full DescriptionError Spending Function: See alpha spending function. Browse Other Glossary Entries
View Full DescriptionInterim Monitoring: In clinical trials of medical treatments or devices, a traditional fixed sample design establishes a fixed number of subjects or outcomes that must be observed. In a trial that uses interim monitoring, the sample size is not fixed in advance. Rather, periodic looks are taken at the accruing...
View Full DescriptionLan-Demets Spending Function: See alpha spending function. Browse Other Glossary Entries
View Full DescriptionLatin Square: The Latin Square is a square array in which every letter or symbol appears exactly one in each row and in each column. B C D A C D A B D A B C A B C D Browse Other Glossary Entries
View Full DescriptionLongitudinal Analysis: Longitudinal analysis is concerned with statistical inference from longitudinal data Browse Other Glossary Entries
View Full DescriptionLongitudinal Data: Longitudinal data refer to observations of given units made over time. A simple example of longitudinal data is the gross annual income of, say, 1000 households from New York City for the years 1991-2000. See also: cross-sectional data , panel data , Cohort Data Browse Other Glossary Entries
View Full DescriptionLongitudinal study: Longitudinal studies are those that record data for subjects or variables over time. If a longitudinal study uses the same subjects at each point where data are recorded, it is a panel study . If a longitudinal study samples from the same group at each point where data...
View Full DescriptionStatistical Glossary Paired Replicates Data: Paired replicates is the simplest form of repeated measures data , when only two measurements are made for each experimental unit. Consider, for example, a study of 2 drugs - A and B - to determine whether they reduce arterial blood pressure. There are 10...
View Full DescriptionPanel Data: A panel data set contains observations on a number of units (e.g. subjects, objects) belonging to different clusters (panels) over time. A simple example of panel data is the values of the gross annual income for each of 1000 households in New York City, 200 from each of...
View Full DescriptionPanel study: A panel study is a longitudinal study that selects a group of subjects then records data for each member of the group at various points in time. See also panel data . Browse Other Glossary Entries
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