Chapter 2

Research Setting:

  • Lab

- A controlled environment specifically designed for research

  • Field

- Happens in a natural, real world setting

Research Design

  • Cross - sectional: data collected at a single point in time

  • Longitudinal: data collected on the same people over time

  • Cross - sequential or cohort - sequential: data collected on different age groups over time

Threats to experiment

  • Lack of precise operational definition

  • An operational definition specifies how a variable will be measured or observed in a study

  • Experimenter bias

  • Researcher’s expectations may influence the results of a study

  • Confirmation bias

  • Placebo effect

  • A placebo is an inactive substance or false treatment like a sugar pill, saline solution, distilled water, sham surgery

  • Placebo effects occur because the person has the expectation or belief that the treatment will be helpful

  • Many threats can be counteracted using a double-blind or masked design

  • There may be issues with reliability and/or validity

  • Reliability refers to the consistency of the measurement

  • Validity refers to whether the measure accurately measures what it is intended to there are many different types of reliability and validity

Internal Validity

  • The extent to which the treatment, rather than a confounding or third variable, accounts for the effect or relationship

External Validity

  • The extent to which results can be generalized across people, settings, and time

  • Ecological validity


Correlation

  • Correlation coefficient ranges from -1 to 1

  • positive relationship

variables change in the same direction

  • Negative relationship

variables change in the opposite directions

Spurious correlation

Relationship between two variables that appears to be causually connected but its actually due to an unseen, third factor confounding variable that influences both

Research Ethics

  • Long history of unethical research

    • World War II and Nazi experiments

    • “Tuskegee Study of Untreated Syphilis in the Negro Male”

  • We can’t always anticipate risk or harm

    • Milgram’s Obedience to Authority study

    • Zimbardo’s Stanford Prison Experiment

  • Led to the creation of codes of research ethics

    • Nuremberg code

    • Belmont Report