Week 12 - Collective Behavior

Today’s Dad Joke

When I was young, we were really poor. My family could only afford a second-hand calculator, which was missing the “X” button.

Times were hard.

Housekeeping

• Exam next week
• One page of notes, front and back (printed)
  • Short response + multiple choice
• Making networks without grids
  • set_graph_style(family='sans') or theme_graph()

AI Conversation

• There is a tension
  • Universities are meant to educate and credential
  • AI is an amazing tutor
  • But it can also be used to substitute for learning and make evaluation much more difficult
  • AI can help us to understand deeper, or to pretend that we understand deeper.

AI Conversation

• Imagine that you were the instructor for a class like COM 411. How would you design the class to encourage learning given today’s technological environment?

Final Project

• Timing for final project
  • Don’t wait - get started now!
  • Reach out if you get stuck
• Look at example projects from the past
• Not all visualizations have to be networks
• Concepts + Visualizations

Mini-lecture on Wisdom of Crowds and Collective Intelligence

Collective Intelligence

• Idea that groups can be smarter than the smartest person in the group
• Sometimes it’s simple; e.g, aggregating information from multiple sources
• Sometimes there is an emergent property, where the group thinks and behaves differently

Ants

Organizations

• While organizations are much more hierarchical than ants, they can still have emergent properties
• Partially a function of history, partially of the structure of the organization
• Even a culture everyone dislikes can be hard to change
• E.g., metric system, QWERTY keyboards

Cities

• High-level decisions about zoning, infrastructure, etc. but the character of a city is emergent
• Jane Jacobs: “The Death and Life of Great American Cities”

Wisdom of Crowds Activity

• Get out a piece of paper
• Guess how many pages are in this book and write down your guess
• Tell your guess (and no other information) to the two people on either side of you
• Guess again how many pages are in the book and write it on a new line (Guess 2)

Activity 2

• Guess 3: Guess the pages in this book
• Two random people will tell us their guess
• Guess 4: Guess the pages again for this book

Collective understanding and decision-making

• Wisdom of crowds is idea that in many contexts, the average is a really good guess!
• What is groupthink? Have you seen examples? How might this relate?
• Dr. Josh Becker et al. show that in some cases, communication can help
  • Those whose guesses are worst move the most
  • Divorced from other social relationships (not multiplex)

Results

Decentralized network

Centralized network

Connections to other network concepts

• How does this relate to our week on small group networks?
  • Transactive memory
  • Hierarchy
  • Centralization
• How could you design a group / network to get the benefits of the wisdom of crowds?
• When would you expect a wisdom of crowds approach to work well?
• When would you expect it to fail?

Plan for Today

• Exam Review

Exam Review

• Visualization / ggraph
• Look at code and explain what it will look like
• Find the bug in code

Example

• What code produces this graph?

G |>
  mutate(centrality = centrality_degree()) |>
  activate(edges) |>
  ggraph() +
  geom_edge_fan(color = 'purple') +
  geom_node_point(aes(size = centrality), color = 'green')

Exam Review

What would this code do?

G |>
  activate(nodes) |>
  mutate(ec = centrality_eigen()) |>
  filter(ec > 1) |>
  ggraph() +
  geom_edge_fan(color = 'orange') +
  geom_node_point(aes(size = ec), color = 'green')

Exam Review

• Centrality
• Network representations (Edgelists and matrices)
• Network formation
  • Homophily, focus theory, transitivity, social exchange theory, etc.
• Tie strength and small worlds

Exam Review

• Power and social capital
• Contagion and diffusion
• Centrality
• Bipartite networks and projections
• Random rewirings

Exam Review

• Friendship paradox
• Strength of weak ties