Transcript of "Lesson 1 research methods (variables & hypothesis)"
Experimental Research: Where cause meets effect Lesson 1: Research Methods (Variables and Hypothesising)Friday, 11 January 2013
Objectives: Lesson 1 Outline the scientific method in psychological research • Identify variables including the dependent, independent, extraneous and confounding variables • Construct a research and operational hypothesis of a research questionFriday, 11 January 2013
Characteristics of an experiment • IV is the variable selected and tested by the researcher to assess effects on the DV (i.e participants responses) • It is assumed that changes in the DV will result after exposure to the IV. • IV and potential unwanted variables (e.g extranious variables) are controlled • Use of random allocation of participants to different conditions (groups) ensures uniform distributed participant characteristics that can affect the DV.Friday, 11 January 2013
Variables Independent variable – the variable that is changed by the experimenter, interested in its effect. We want to see the effect of the IV on the DV Dependent Variable – measures the effect of the IV, see if the IV has effected the DVFriday, 11 January 2013
Activity: Research Question: Does drinking alcohol effect driving? Identify the IV and DV Write a research hypothesisFriday, 11 January 2013
Experimental group and Control group Experimental group: Participants exposed to the treatment condition, i.e the IV manipulation. Control group: Participants not exposed to the IV manipulation.Friday, 11 January 2013
The Research Hypothesis Hypothesis – a testable prediction relating to the outcome of the research being conducted, a prediction that one variable (IV) will effect another variable (DV) in a certain way.Friday, 11 January 2013
Example Research Question: Does smoking marijuana effect driving performance? Independent Variable - smoking marijuana Dependent Variable - driving performance It was hypothesised that participants who smoke marijuana will perform worse on a driving test as compared to participants who have not smoked marijuanaFriday, 11 January 2013
Operationalisation of Variables Variables that need to be operationalised Smoking Marijuana Driving Performance The population – who we are testing Operational Definitions Smoking Marijuana – smoking one joint containing 500 milligrams of pure marijuana (not mixed with tobacco) 20 minutes before taking a driving test Driving Performance -% score on VIC Roads, “Are you Road Ready?”driving simulator Population - Victorian drivers aged 18 – 25Friday, 11 January 2013
The Operational Hypothesis It was hypothesised that Victorian drivers aged 18 – 25 who have smoked marijuana (smoking one joint containing 500 milligrams of pure marijuana 20 minutes before taking a driving test) will perform worse on a driving test (obtain a lower % score on the VIC Roads “Are you Road Ready?” driving simulator) compared to participants who have not smoked marijuana. Note: Not required according to VCAA - however you do need to be able to operationalise the variables!!Friday, 11 January 2013
Activity: Research Question: Does drinking red cordial make children hyperactive? Operationalise the independent and dependent variablesFriday, 11 January 2013
Extraneous and Confounding Variables Extraneous Variable: Any variable, other than the IV, that can cause a change in the DV and therefore affect the results of an experiment in an unwanted way. An extraneous variable may become a confounding variable. Confounding variable: Any variable, other than the IV, that is uncontrolled and allowed to change together with the IV, thereby having an unwanted effect on the DVFriday, 11 January 2013
Watch Clip Below SummaryFriday, 11 January 2013
Activity: 1)Identify one extraneous variable. 2)Identify an ethical breach in the experiment.Friday, 11 January 2013
Revision Do drivers who have more experience behind the wheel have less accidents than less experienced drivers? IV = DV = EV = Research Hypothesis: Operationalised Variables: IV: DV:Friday, 11 January 2013
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