Ninth Edition CoverGraziano & Raulin
Research Methods (9th edition)

Glossary Items Starting with "L"

Laboratory Animal Care Committee
A formalized committee that reviews every research proposal that involves animals for ethical issues. Every research center that conducts animal research must have a local Laboratory Animal Care Committee.

Latin square design
A procedure used to provide a measure of counterbalancing in a within-subjects design. Instead of using all possible orders of presentation, as in complete counterbalancing, a Latin square design uses a set of orders that ensures that every experimental condition appears equally often in every position.

levels of constraint
Degree of systematic control applied in research. The labels assigned to these levels of constraint are naturalistic, case-study, correlational, differential, and experimental.

levels of headings
The mechanism used in published research articles for organizing the report. Levels of headings are similar to an outline, with the various sections and subsections of the report representing different levels of the outline. 


Likert-scale items
In Likert scales, each item is presented on a continuum. For example, the scale may range from "strongly agree" to "strongly disagree."

linear relationship
Relationship between two or more variables that, when plotted in a standard coordinate system, tend to cluster around a straight line. Most correlation coefficients are sensitive only to linear relationships between variables.

list server
A mechanism that permits continuous electronic conversations between people who may be spread all over the world. Electronic mail messages sent to a list server are distributed to everyone on a distribution list, allowing the easy exchange of ideas among large groups of people. 
Set of operations that can be applied to statements and conclusions drawn from those statements to determine the internal accuracy of the conclusions.

longitudinal (panel) design
A research design used in developmental psychology in which a group of participants is followed over time, with the dependent measures repeated during follow-up testing. This design is often contrasted with cross-sectional designs.

longitudinal research
Research in which a longitudinal research design is used.