a quasi-experimental design in which the responses of a treatment group and a control group are compared on measures collected at the beginning and end of the research .
What does the concept of nonequivalent groups mean?
the concept of nonequivalent groups means that the number of participants is different from one group to another .
What is a nonequivalent control group design example?
Imagine, for example, a researcher who wants to evaluate a new method of teaching fractions to third graders . ... This design would be a nonequivalent groups design because the students are not randomly assigned to classes by the researcher, which means there could be important differences between them.
What is the purpose of Nonequivalent Group designs?
The posttest only nonequivalent control group design is used to show that a treatment was effective in a preexisting treatment group . Thos in the preexisting treatment group are compared to a control group of similar types of persons.
What is the difference between a nonequivalent control group design and a pretest posttest control group design?
Using a pretest-posttest design with switching replication design , nonequivalent groups are administered a pretest of the dependent variable, then one group receives a treatment while a nonequivalent control group does not receive a treatment, the dependent variable is assessed again, and then the treatment is added ...
What are the advantages of having a control group?
A scientific control group is an essential part of many research designs, allowing researchers to minimize the effect of all variables except the independent variable . The control group, receiving no intervention, is used as a baseline to compare groups and assess the effect of that intervention.
Why does a good experiment include a control group?
Inclusion of a control group greatly strengthens researchers’ ability to draw conclusions from a study . ... A typical use of a control group is in an experiment in which the effect of a treatment is unknown and comparisons between the control group and the experimental group are used to measure the effect of the treatment.
What is the primary advantage of ABAB design?
ABAB designs have the benefit of an additional demonstration of experimental control with the reimplementation of the intervention . Additionally, many clinicians/educators prefer the ABAB design because the investigation ends with a treatment phase rather than the absence of an intervention.
What is post test control group design?
The posttest-only control group design is a research design in which there are at least two groups , one of which does not receive a treatment or intervention, and data are collected on the outcome measure after the treatment or intervention.
What are the threats to internal validity of a nonequivalent groups design?
Basic threats to internal validity include: history, maturation, testing, instrumentation, regression to the mean, and attrition . These threats were described in more detail in Chapter 10. In a one-group posttest-only design, a treatment occurs and afterward the dependent variable is measured once (X, O 1 ).
What are the 4 types of research design?
There are four main types of Quantitative research: Descriptive, Correlational, Causal-Comparative/Quasi-Experimental, and Experimental Research . attempts to establish cause- effect relationships among the variables. These types of design are very similar to true experiments, but with some key differences.
Does quasi-experimental have a control group?
“Quasi-experimental research is similar to experimental research in that there is manipulation of an independent variable. It differs from experimental research because either there is no control group , no random selection, no random assignment, and/or no active manipulation.”
What is an interrupted time series study?
Interrupted time series analysis (ITS), sometimes known as quasi-experimental time series analysis, is a method of statistical analysis involving tracking a long-term period before and after a point of intervention to assess the intervention’s effects .
What is an example of a quasi-experimental design?
This is the most common type of quasi-experimental design. Example: Nonequivalent groups design You hypothesize that a new after-school program will lead to higher grades . You choose two similar groups of children who attend different schools, one of which implements the new program while the other does not.
Is quasi-experimental quantitative or qualitative?
Quasi experiments resemble quantitative and qualitative experiments , but lack random allocation of groups or proper controls, so firm statistical analysis can be very difficult.
What are the advantages of quasi-experimental design?
The greatest advantages of quasi-experimental studies are that they are less expensive and require fewer resources compared with individual randomized controlled trials (RCTs) or cluster randomized trials.
