Moderation and Mediation

Overview of DEI and Organizational Changes

  • Massive layoffs in health organizations:
    • U.S. Department of Health and Human Services announced a reduction of 10,000 employees across agencies (includes FDA, CDC, NIH, CMS).
    • Total workforce shrinks from 82,000 to 62,000.
    • This follows an additional 10,000 voluntary departures.

DEI Initiatives

  • DEI stands for: Diversity, Equity, and Inclusion
    • Focused on fair treatment for individuals from historically underrepresented groups.
    • Recent cancellation of DEI grants, e.g., a randomized controlled trial in medical schools aimed at testing diversity training.

Importance of Advocacy

  • Share information on these issues widely.
  • Advocate for science and contact representatives.
    • Recommended using 5 Calls app: Reach out to local representatives such as Summer Lee, John Fetterman, and Dave McCormick.

Examination Reminders

  • Office hours today from 2:30-3:30 PM: Review for the upcoming exam.
  • Homework (HW 9) on Factorial Experiments due one week from today.
  • Only 5 more lectures with new material left.

Key Concepts in Research Design

  • Main Effect: The overall effect of one Independent Variable (IV) on the Dependent Variable (DV).
  • Interaction Effect: Indicates the effect of one IV on the DV depends on the level of another IV.
    • Example rate of enjoyment in food contexts: Interaction plotted between food condiments and enjoyment level.

Understanding Moderation

  • Moderation is defined as an interaction between variables.
    • Moderators influence the relationship between two other variables.
    • Example: The type of condiment used affects enjoyment of food.
  • Characteristics of Moderators:
    • Change the strength of an effect between two variables.
    • Can strengthen, weaken, promote, dampen, exacerbate, or protect the relationships.
Example of Moderation
  • A positive correlation between age and happiness where gender moderates this correlation, indicating stronger associations for women.

Potential Moderators

  • Various relationships can have moderating variables:
    • Age and intelligence
    • Income and happiness
    • Motivation and success

Moderation vs. Mediation

  • Moderation asks:
    • When, where, and for whom does the effect occur?
    • Focus is on understanding the contingencies and dependencies.
  • Mediation asks:
    • How and why does the effect occur?
    • Conveys the processes explaining the phenomenon.

Exploring Mediation

  • Questions regarding social media use and depression:
    • Why is there an association?
    • What explains this relationship?
    • How does the association operate?
Potential Mediators
  • Similar structured inquiries for:
    • Age and intelligence
    • Income and happiness
    • Motivation and success

Key Takeaways

  • Interaction effects dictate that the impact of one IV on the DV may vary due to changes in another IV.
  • Moderation = Interaction
  • Moderators influence the strength of variable relationships.
  • Mediators clarify reasons behind associations of variables.