1 / 17

Research Methods Outline

Research Methods Outline. The Experimental Method Manipulation Random Assignment Internal and External Validity Class Experiment Questionnaire. The Experimental Method. Used to establish cause-effect relations Group dynamics laboratory experiments Ad hoc groups Experimental confederates.

dwentz
Download Presentation

Research Methods Outline

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Research MethodsOutline • The Experimental Method • Manipulation • Random Assignment • Internal and External Validity • Class Experiment • Questionnaire

  2. The Experimental Method • Used to establish cause-effect relations • Group dynamics laboratory experiments • Ad hoc groups • Experimental confederates

  3. The Experimental Method • Example: Johnny Rocco Study (Schachter, 1951) • Groups to discuss a delinquent • Confederates: mode, deviate, slider • Results: S's liked the conforming members best. All disliked the deviate the most.

  4. The Experimental Method • Two key features 1) Manipulation 2) Random assignment

  5. Manipulation • “Create” two or more treatment conditions • Independent variable: • Controlled (manipulated) by the experimenter • the hypothesized “cause’ • Dependent variable: • Measured by the experimenter (the outcome) • the outcome of “effect”

  6. Manipulating the IV • Lewin, Lippitt, and White leadership study • Independent variable • Type of leader • Autocratic, democratic, or laissez-faire • Dependent variable • Time spent working, amount of hostility, liking for the leader…

  7. Manipulation & Experimental Control • Experiments require that everything in the setting stay the same except for the independent variable • Example: • Instructions delivered the same • Experimenters the same across conditions

  8. Random Assignment • Experiments must have at least 2 treatment conditions • Treatment (experimental) group • Control group • A given participant must be equally likely to be assigned to any of the given groups • Random number table • Flip a coin

  9. Avoiding Experimental Confounds • Experimental control and random assignment are designed to ensure that extraneous variables (confounds) will not systematically bias the study results • Examples of experimental confounds: • Time of day • Gender of researcher • Race of participant

  10. Identify Key Experimental Features • Social loafing refers to people’s tendency to slack on group tasks. In one study on social loafing (Latane, Williams and Harkins) college participants cheered alone, and in groups of 2, 4, or 6 ppl. They were told to cheer as loud as possible at specific times so researchers could determine how much noise people made in social settings. The amount of noise made by each participant dropped as group size increased. • 1) What is the IV? • 2) What is the DV? • 3) Why is random assignment important here?

  11. Internal and External Validity • Internal validity • The extent to which the observed effect is caused only by the experimental treatment condition • The ability to draw conclusions about a causal relationship from our data • Experiments usually high in this • External validity • The extent to which the results can be applied to and across different persons, settings and times • AKA generalizability • Experiments often low in this

  12. Generalizing From the Lab Setting • Mundane realism • The extent to which an experiment is similar to real-life situations • Psychological realism • The extent to which an experiment triggers relevant psychological and group processes • Key point • Lab experiments not automatically artificial • When an experiment lacks mundane realism it may be very realistic in terms of psychological realism

  13. Field Experiments • Field experiments • Experiments conducted in real-world settings • Example: Lewin, Lippitt, and White leader study • Uncommon in real-world settings • Hard to assign people to independent variable groups • Hard to control groups so that everything is the same except for the IV

  14. Assess Internal & External Validity • Does lighting affect productivity? • Study 1: • Give employees in a well-lit office and those in a dim office a production task. Measure and compare their productivity (how quickly and accurately they perform the task). • Study 2: • Give people a production task in a laboratory. The lab room is either bright or dim. Measure and compare their productivity (how quickly and accurately they perform the task).

  15. The Tradeoff • Real life situations • High external validity • Hard to rule out other explanations • Low internal validity • Lab settings • High internal validity • Often artificial and findings can’t be generalized • Low external validity

  16. Class Experiment • Students randomly assigned to condition • Heads: Stay in class and work with groups • Tails: Go outside and work alone • Task: Brainstorm on ‘uses for a brick’

More Related