Pearson Edexcel · GCSE · Psychology

    Course version: 1PS0 · Version from Sept 2017

    Be able to identify: a. an independent variable (IV) b. a dependent…

    Full specification wording

    Designing psychological research: 11.1.1 Be able to identify: a. an independent variable (IV) b. a dependent variable (DV) c. extraneous variables, including (i) situational variables (ii) participant variables

    In psychological research, variables must be clearly identified.

    Checked against the Pearson Edexcel 1PS0 specification (opens in a new tab) on .

    • Point 1 of 17
    • 4 key terms

    Study notes

    From the checked teaching notes for this specification point.

    The idea

    In psychological research, variables must be clearly identified. The independent variable (IV) is the factor manipulated by the researcher to observe its effect (e.g., type of music played). The dependent variable (DV) is the factor measured to assess the outcome of the IV manipulation (e.g., number of words recalled). Extraneous variables are other factors that could affect the DV if not controlled. These include situational variables, which are environmental factors like noise or lighting, and participant variables, which are individual differences among subjects, such as age or intelligence. Controlling these extraneous variables ensures that changes in the DV are solely caused by the IV, establishing valid cause and effect.

    What earns the marks

    • Identify the independent variable (IV) as the factor manipulated or changed by the researcher.
    • Identify the dependent variable (DV) as the factor measured by the researcher to assess the outcome.
    • Define extraneous variables as factors other than the IV that could affect the DV if not controlled.
    • Distinguish situational variables (environmental factors) from participant variables (individual differences).
    • Explain the importance of controlling extraneous variables to establish a valid cause-and-effect relationship.

    Common mistakes and how to put them right

    • Confusing the IV and the DV.

      Put it right: The IV is what the researcher changes (manipulates), and the DV is what the researcher measures (the data collected).

    • Defining extraneous variables as variables that have already affected the results.

      Put it right: Extraneous variables are variables that could affect the results if they are not controlled; if they do affect the results, they become confounding variables.

    • Classifying time of day as a participant variable.

      Put it right: Time of day is a situational variable because it relates to the environment of the study, not an inherent characteristic of the participant.

    Exam tips

    • When asked to identify variables from a scenario, always state them exactly as they are operationalised in the text.
    • Use the mnemonic 'I Change, Data Measures' to remember the difference between the independent and dependent variables.
    • Be prepared to suggest specific ways to control situational and participant variables in a given research scenario.

    Try the lesson

    The start of the Designing psychological research: 11.1.1 Be able to identify: a. an independent variable (IV) b. a dependent variable (DV) c. extraneous variables, including (i) situational variables (ii) participant variables lesson, made from checked teaching notes for this specification point.

    Have a go first

    A researcher investigates whether drinking coffee improves memory recall. Participants either drink coffee or water, and then complete a memory test. Which of the following is the independent variable in this study?

    Listen

    In psychological research, variables must be clearly identified. The independent variable (IV) is the factor manipulated by the researcher to observe its effect (e.g., type of music played). The dependent variable (DV) is the factor measured to assess the outcome of the IV manipulation (e.g., number of words recalled). Extraneous variables are other factors that could affect the DV if not controlled. These include situational variables, which are environmental factors like noise or lighting, and participant variables, which are individual differences among subjects, such as age or intelligence. Controlling these extraneous variables ensures that changes in the DV are solely caused by the IV, establishing valid cause and effect. A strong answer earns marks for these points. Identify the independent variable (IV) as the factor manipulated or changed by the researcher. Identify the dependent variable (DV) as the factor measured by the researcher to assess the outcome. Define extraneous variables as factors other than the IV that could affect the DV if not controlled. Distinguish situational variables (environmental factors) from participant variables (individual differences). A common slip: Confusing the IV and the DV. Instead, the IV is what the researcher changes (manipulates), and the DV is what the researcher measures (the data collected). Exam tip: When asked to identify variables from a scenario, always state them exactly as they are operationalised in the text.

    See it

    A top-down flowchart. At the top, a node reads 'Researcher manipulates the IV' and points down to 'IV affects the DV', which points down to 'Researcher measures the DV'. Separately, a node reads 'Extraneous variables could affect the DV' and branches into two nodes: 'Situational variables: environmental factors' and 'Participant variables: individual differences'. Both of these point down to 'Control extraneous variables', which points down to 'Changes in the DV caused solely by the IV', which finally points down to 'Valid cause and effect'.
    Shows how the IV is manipulated and the DV measured, how situational and participant extraneous variables could affect the DV, and how controlling them establishes valid cause and effect.

    Key words

    Say what each word means before you turn the card.

    Independent variable (IV)

    Try answering aloud or in your head before turning the card.

    Dependent variable (DV)

    Try answering aloud or in your head before turning the card.

    Extraneous variables

    Try answering aloud or in your head before turning the card.

    Situational variables

    Try answering aloud or in your head before turning the card.

    See every definition
    Independent variable (IV)
    The factor manipulated by the researcher to observe its effect.
    Dependent variable (DV)
    The factor measured to assess the outcome of the IV manipulation.
    Extraneous variables
    Other factors that could affect the DV if not controlled.
    Situational variables
    Environmental factors like noise or lighting.

    Label the diagram

    Some boxes have lost their names. Pick the right name for each number.

    The diagram again, with 3 boxes numbered instead of named. A top-down flowchart. At the top, a node reads 'Researcher manipulates the IV' and points down to 'IV affects the DV', which points down to 'Researcher measures the DV'. Separately, a node reads 'Extraneous variables could affect the DV' and branches into two nodes: 'Situational variables: environmental factors' and 'Participant variables: individual differences'. Both of these point down to 'Control extraneous variables', which points down to 'Changes in the DV caused solely by the IV', which finally points down to 'Valid cause and effect'.

    • 1Box 1

    • 2Box 2

    • 3Box 3

    0 of 3 labelled

    There is more to this lesson

    The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.

    Carry on with the full lesson

    A week of Premium from your first lesson · Then the free plan continues · No card, no charge

    Test your understanding of Designing psychological research: 11.1.1 Be able to identify: a. an independent variable (IV) b. a dependent variable (DV) c. extraneous variables, including (i) situational variables (ii) participant variables

    Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.

    Take topic quiz

    A week of Premium from your first lesson · Then the free plan continues · No card, no charge

    Start free

    Cookies on MasteryMind

    Essential cookies keep you signed in.

    Analytics and advertising cookies stay off unless you accept.

    Read our Privacy Policy.