Extraneous Variables are undesirable variables that influence the relationship between the variables that an experimenter is examining. These variables are undesirable because they add error to an experiment. A major goal in research design is to decrease or control the influence of extraneous Variables as much as possible. (Psychology world, 2017). The extraneous variables can be hold constant by creating a standardized environment and procedure so that all variables are the same in each condition and therefore cannot be confounding. These variables exist in all studies and can interfere with obtaining a clear understanding of the relationship among the study variables. For example, if a study focused on the effect of relaxation therapy on the perception of incisional pain, the researchers would have to control the extraneous variables, such as type of surgical incision and time, amount, and type of pain medication administered after surgery, to prevent their influence on the patient’s perception of pain. Selecting only patients with abdominal incisions who are hospitalized and receiving only one type of pain medication intravenously after surgery would control some of these extraneous variables. Controlling extraneous variables enables researchers to determine the effects of an intervention or treatment on study outcomes more accurately. (Grove, Gray & Burns, 2015).
Quantitative research is a type of formal, objective type of research and generates numerical information about concepts and relationships between variables and includes descriptive, correlational, quasi-experimental and experimental (Burns & Grove, 2011).
The type of quantitative research used is based on the amount information the researcher has on the subject before the experiment. If a researcher knows little about the topic they may begin with descriptive to gather better information then move on to correlational, quasi-experimental or experimental studies (Burns & Grove, 2011). Descriptive research is typically without manipulation and leads to further quantitative studies (Burns & Grove, 2011).
Correlation studies describe relationships between variables in a positive, negative relationship or no relationship such as smoking cigarettes negatively affecting the smoker’s life span however does not study to which a degree or the exact cause and often will lead to a more extensive study such as quasi-experimental or experimental research (Burns & Grove, 2011).
Quasi-experimental research examines relationships to better determine a cause-and-effect relationship between variables and involve implementing a treatment to a concern and evaluating the effects (Burns & Grove, 2011). Quasi-experimental research involves less control of variables than strict experimental research and often utilize humans or patients as a variable and is most often used in nursing research (Burns & Grove, 2011). An example of quasi-experimental research can include a certain exercise program for cardiac rehab patients post CABG and the effects on improving the health or assisting in the rehabilitation.