Slowing Growth of Wikipedia:Implications for the Future

Bongwon Suh, Gregorio Convertino, Ed H. Chi, Peter Pirolli

Augmented Social Cognition Area

Palo Alto Research Center

What’s Happening to Contribution Patterns inside Wikipedia?

1. What’re the Global Activity level patterns?

2. What’re activity patterns by Editor Classes?

3. Are the Population Sizes stable? Analysis of Population by Editor Class

Exponential Growth of Wikipedia was an accepted ‘fact’

Number of Articles (Log Scale)

http://en.wikipedia.org/wiki/Wikipedia:Modelling_Wikipedia’s_growth

Growth of Edits

Monthly Edits

Growth of Active EditorsActive Editors

Something happened in early 2007

Monthly Edits

Slowing Growth in Global Activity

*In thousands Monthly Active Editors

What’s Happening to Contribution Patterns inside Wikipedia?

1. What’re the Global Activity level patterns?

2. What’re activity patterns by Editor Classes?

3. Are the Population Sizes stable? Analysis of Population by Editor Class

Activity By Editor Classes

Monthly Edits by Editor Class (in thousands)

Monthly % of Edits by Editor Class

Reverts in Wikipedia

Undoing the effects of one or more edits– The page being restored to a version

that existed sometime previously. – Reverting may also refer to any action

that reverses the actions of other editors.– Fighting vandalism– This analysis exclude vandalism to

model “resistance”

Ratio of Reverted Contributions

Monthly Ratio of Reverted Edits

Growing Resistance

Increased resistance from the Wikipedia community to activities by occasional editors

Disparity of treatment of edits– Occasional editors have been

reverted in a higher rate

Photo: http://lianza2009.wordpress.com/

What’s Happening to Contribution Patterns inside Wikipedia?

1. What’re the Global Activity level patterns?

2. What’re activity patterns by Editor Classes?

3. Are the Population Sizes stable? Analysis of Population by Editor Class

Population Analysis

Monthly Active Editors

Population by Editor Class

Some Key Takeaways

1. What’re the Global Activity level patterns?– No longer following an exponential growth curve.– Logistic growth is now a better explanation

2. What’re activity patterns by Editor Classes?– Middle class decreasing their proportion of edits– Different editor classes experience differing

resistances

3. Are the Population Sizes stable? – Middle class a smaller portion of the pyramid

Exponential Growth Model

Exponential growth model– Growth rate depends on the current N

Preferential Attachment: Edits beget edits– The more number of previous edits, the more number of

new edits– r, growth rate of the population€

dN

dt= r *N

Logistic Growth Model

Ecological population growth model– r, growth rate of the population– K, carrying capacity (due to resource limitation)

€

dN

dt= rN(1−

N

K)

Number of New Articles

Follows a logistic growth curve

New Article

A modified logistic model

Carrying Capacity as a function of time.

Struggle for Existence - Darwin

Biological system– Competition increases as

population hit the limits of the ecology

– Advantage go to members of the population that have competitive dominance over others

Analogy– Limited opportunities to make

novel contributions– Increased patterns of conflict and

dominance

Population Dynamics Model

Ecological growth model– r, growth rate of the population– K, carrying capacity (due to resource

limitation) r-Strategist

– Growth or exploitation– Less-crowded niches / produce many

offspring K-Strategist

– Conservation– Strong competitors in crowded niches /

invest more heavily in fewer offspring€

dN

dt= rN(1−

N

K)

[Gunderson & Holling 2001]

Factors Affecting the Growth of Wikipedia

People-ware– Growing resistance to new content– Coordination cost and bureaucracy

Knowledge-ware– Availability of easy topics to write about

Tool-ware– Quality of tools used by editors and admins

Thank you!

ed.chi@parc.com

http://asc-parc.blogspot.com

Augmented Social Cognition Area

Palo Alto Research Center

Monthly Ratio of Reverted Edits

http://strategy.wikipedia.org