Independent and Dependent Variables (IV & DV) — Study Notes

Independent Variable (IV)

• In the transcript, there is a discussion of experimental variables: those factors that are being selected, manipulated, or observed.

• There are two types discussed for the purpose of presenting here. The first is the Independent Variable (IV).

• IV stands for Independent Variable. It is also referred to as the treatment variable.

• Exam note: write down that the IV is the treatment variable; it is mentioned on the exam.

• The transcript emphasizes that if you have a terrific memory, you should write it down; otherwise, you might forget.

• The IV is described as the manipulated variable in the experiment (the one the researcher changes).

• The IV is also described in the transcript as the controlled variable of the experiment and the one that is manipulated. This wording appears in the transcript and is pointed out as something you should remember.

• The IV is the variable that the researcher is going to be manipulating.

• The transcript uses the phrase “the funnier” as an unclear reference; the intended meaning is the factor or variable that is being manipulated.

• The IV is hypothesized, as stated in the transcript, to cause an effect on another variable.

• The variable affected by the IV is the Dependent Variable (DV).

• The IV is described as the treatment variable, reinforcing the idea that it is the manipulated factor in the study.

• The IV is the factor that the researcher chooses to vary in order to observe its impact on the outcome measured by the DV.

• The role of the IV is to cause a change in the DV, establishing a cause-and-effect possibility if confounds are controlled.

• Examples (inferred from the concept): different doses or conditions of a treatment, different teaching methods, or different environmental conditions (these are typical ways researchers manipulate the IV to observe effects on the DV).

Dependent Variable (DV)

• The DV is the variable that is measured in the experiment.

• The DV is described as the dependent variable and is also called the outcome variable.

• The DV is the variable that the researcher measures to assess the effect of the IV.

• The transcript explicitly states that the dependent variable is the variable that is measured and that it is the outcome variable.

• The DV is also referred to as the outcome variable, reinforcing that it represents the measured effect of the IV.

• The phrase in the transcript emphasizes that the DV is the outcome that results from the manipulation of the IV.

• The relationship: IV → DV, where the DV is the observed outcome used to determine if the IV had an effect.

Terminology and synonyms

• Independent Variable (IV) synonyms: independent variable, treatment variable, manipulated variable.

• Dependent Variable (DV) synonyms: dependent variable, outcome variable, measured variable.

• The transcript highlights that using multiple descriptors (IV/treatment variable; DV/outcome variable) helps remember their roles in an experiment.

Conceptual relationship and significance

• The IV is the factor that the researcher manipulates to test its effect on the DV.

• The DV is the variable that is measured to determine the effect of the IV.

• The basic causal claim in such experiments is that changes in the IV cause changes in the DV (under proper control of other factors).

• The transcript emphasizes that the IV is “hypothesized to cause an effect on another variable” (the DV).

• The DV is the outcome that reflects the effect of the manipulation on the observed measure.

Clarifications and potential confusion (notes from the transcript)

• The transcript uses the term “the controlled variable of the experiment” to describe the IV. In standard experimental terminology, a control variable is a variable kept constant, not the manipulated variable. The transcript’s phrasing mixes these concepts, so be aware of the distinction:

  • Independent Variable (IV): manipulated variable.

  • Control Variables: variables kept constant to prevent confounding.

• The transcript contains some garbled phrases (e.g., “Is there a night?” and “Like the funnier”). These appear to be transcription errors and do not contribute to the core definitions.

• The emphasis on writing down the definitions is to ensure you remember the exam expectations for IV and DV.

Practical implications and exam relevance

• For exam preparation, memorize:

  • IV = independent variable = treatment variable = manipulated variable.

  • DV = dependent variable = outcome variable = measured variable.

• Understanding these roles helps in designing experiments and interpreting results, particularly in assessing whether changes in the IV are associated with changes in the DV.

• When reporting results, clearly state which variable was manipulated (IV) and which variable was measured (DV) to convey the causal claim (subject to control of confounds).