Kaarten: Methodology - Chapter 10 - The Non-Experimental and Quasi-Experimental Strategies | Quizlet

A non-manipulated variable

Type of variable that defines the groups or conditions being compared in a non-experimental or quasi-experimental research strategy. Usually a participant variable (college graduate vs. no college) or a time variable (before vs. after treatment).

Statistically significant

When it is very unlikely that the difference between the group of scores would occur if there were no corresponding difference in the population.

Pre-post designs

Also known as within-subjects design

Non-equivalent group designs

Also known as between-subjects design

Non-equivalent group designs

A research study where different groups of participants are formed under circumstances that do not permit the researcher to control (no random assignment possible) the assignment of individuals to groups.

Differential research design

A (non-experimental) research study that simply compares pre-existing groups. By using a participants' characteristic such as gender, ethnicity, cultural background or personality to automatically assign participants to groups. = no random assignment. A dependent variable is measured for each participant to determine whether the scores of one group are consistently different from the scores of another group.

Non-equivalent control group design

When pre-existing groups (=no random assignment) are used, one to serve in the treatment condition and the other in the control condition

Post-test-only non-equivalent control group design

Compares two non-equivalent groups of participants. One group is observed (measured) after receiving a treatment, and the other groups is measured at the same time but receives no treatment. This is an example of a non-experimental design, also called a static group comparison.

Pre-test-post-test non-equivalent control group design

Compares two non-equivalent groups of participants. One group is measured twice, before and once after, the other group is measured t the same two times but does not receive any treatment. Because this design attempts to limit threats to internal validity, it is classified as quasi experimental.

Differential effects

When history effects differ from one group to another. , e.g.: in a pré-test post-test non equivalent control group design.

Pre-post designs

A research study in which a series of observations is made over time for one group of participants

History, instrumentation, order effects, maturation and statistical regression

Five categories of time-related threats to internal validity

Pre-test-post-test design

The non-experimental research strategy where each individual in a single group of participants is measured once before treatment and once after treatment.

Time series design

A pre-test-post-test design simply modified to minimize the threats (resulting in a quasi-experimental design) of internal validity by having a series of observations for each participant before and after a treatment of event.

Treatment

A manipulation administered by the researcher

Event

An outside occurrence that is not controlled or manipulated by the researcher.

Interrupted time-series design

a study in which the intervening event is not manipulated by the researcher is sometimes called this way

Single case or single-subjects designs

A research design that focuses on a single case, rather than a group of participants are occasionally called single-case time series but are more often classified as

Developmental research designs

Research designed to examine changes in behaviour related to age.

Cross-sectional developmental research design

When different groups of individuals are used, each group representing a different age, The groups are measured at one point in time and then compared.

Cross-sectional

A term used to describe surveys that classify people into different categories or subgroups

cohorts

Individuals that are roughly the same age and have lived in similar environments/circumstances

Cohort effects or generation effects

Environmental factors that differentiate one age group from another, caused by characteristics or experiences other than age.

Longitudinal developmental research design

Examination of development by observing or measuring a group of cohorts over time

Participant attrition / mortality

When participants drop out of a study

Quasi-independent variable

The variable used to differentiate the groups of participants or the groups of scores being compares within the context of non-experimental and quasi-experimental research.

Dependent variable

The variable that is measured to obtain the scores within each group.