Which variable is manipulated in experimental research?

AIIMS Raipur NO - 2019 (Shift-1)

Nursing Research & Statistics (E5)

Easy

Appeared in: AIIMS Raipur NO - 2019 (Shift-1)

Explanation

The independent variable is defined as the condition or factor that a researcher intentionally manipulates, changes, or controls in an experiment.
Its purpose is to determine the effect of this manipulation on another variable, known as the dependent variable.
In clinical trials, the intervention being tested (e.g., a new drug, a specific nursing protocol, a patient education program) is the independent variable.
It is often called the 'manipulated variable' or 'treatment variable' because it is the treatment or intervention being studied.

Option B: The dependent variable is the variable that is measured or observed by the researcher. It is the 'effect' that is expected to change in response to the manipulation of the independent variable.
Option C: The outcome variable is generally a synonym for the dependent variable. It represents the result or outcome that is measured, not the factor that is manipulated.
Option D: The criterion variable is another term for the dependent or outcome variable, most often used in the context of non-experimental, predictive research (e.g., regression analysis). It is the variable being predicted, not manipulated.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Types of variables in experimental research as background academic context rather than a clinical decision trigger.
Understanding the difference between independent and dependent variables is fundamental for nurses to critically appraise research studies and apply evidence-based practice.
When evaluating a study on a new wound care technique (independent variable), a nurse needs to look at its effect on healing time (dependent variable) to decide if the technique is effective.
Nurses often participate in or conduct research. Knowing which variable to manipulate (e.g., frequency of patient turning) and which to measure (e.g., incidence of pressure ulcers) is crucial for a valid study design.

How to Approach the Question

First, identify the key terms in the question: 'manipulated' and 'experimental research'.
Recall the definition of an experiment: a study where a researcher actively intervenes or changes something to see what happens.
The term 'manipulated' is a direct clue. It refers to the action of the researcher controlling or changing a variable.
Connect this action to the definition of an independent variable, which is the 'cause' or 'intervention' that the researcher controls.
Contrast this with the dependent variable, which is the 'effect' or 'outcome' that is measured and is expected to 'depend' on the independent variable.
Recognize that 'outcome' and 'criterion' variables are synonyms for the dependent variable, solidifying that the only manipulated variable is the independent one.

Concept Tested & Keywords

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E6 NursingResearch Suresh Sharma 5e Part 1 pp. 87-89, 86-88

E6 NursingResearch Sukhpal Kaur p. 97-99