Page Rankings What do they teach us Faina

Page Rankings: What do they teach us? Faina Linkov, Ph. D Ronald La. Porte, Ph. D And the Global Health Network Supercourse project University of Pittsburgh

Google’s description of page rank …Page. Rank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important…"

Understanding Page Rank • All search engines assign a value to your site based on inbound links • Google calls this relevancy factor “Page Rank” (PR) - synonymous with popularity ranking • An inbound link is a vote for your page • An outbound link is a vote for the page you’re linking to

Understanding Page Rank • • • A page is assigned PR as soon as it’s indexed The page receiving the most inbound links gets the highest page rank You can pass PR around to pages on your site

Outbound Links • Your popularity is not determined by the sites you link to • Your outbound links affect the popularity of the sites you’re linking to • Internal links and inbound links have the most impact on your popularity • Outbound links help identify you with a hub

Page Rankings and the Supercourse

Supercourse Model: lecture sharing Teacher in Mexico Teacher in Bolivia Teacher in Havana Teacher in Santo Domingo Teacher in Pittsburgh Teacher in San Francisco

Current Status 40000 participants (15 Nobel Prize winners) 151 countries Over 2800 lectures

A Model for Developing and Prescribing Assistive Technology Devices Mary Ellen Buning, Ph. D, OTR/L, ATP Jue Wang, Ph. D University of Pittsburgh

Cardiovascular Epidemiology: Definitions Historical Perspectives and Assessing Risk of CVD Recent trends and population differences in CHD and CHD risk factors Nathan Wong

Topic – Google PPT. lecture ranking for the Supercourse Amebiasis - 2(English) 3 (Spanish) Communicable Disease and disasters - 3/372 Cardiovascular epidemiology - 1&2/9730 Diabetes epidemiology - 3/13, 000 Evidenced based public health - 1/158 Global Health - 1&2/3, 820, 000 Indian Health - 1&2/56, 000 Infectious disease epidemiology - 1/21, 000 Islamic/Arab health - 2/537 Information on the Web - 1/78 Meta Analysis - 6/116, 000 Occupation Cancer - 3/18, 000 Pakistani Health - 6&7/18, 500 Pitt. edu - 2/2, 400, 000 Primordial Prevention - 1/126 Russian health - 2&3/19, 000 Tsunami - 11/31, 000

Health (this is a search on the whole web for the term "health" (985, 000 pages) NIH = 3 WHO = 40 CDC = 220 PAHO= 224

Global health (328, 000 pages) US AID 3 Gates 4 Supercourse 8 CDC 12 WHO 67 NIH 70 PAHO >300

Page Rankings within NIH search term, overall , and then only for the Institutes All NLM NCCAM NIMH NHLBI CIT CSR NIAID NEI NICHD NIAMS NIDA NIDDK NINDS NIAAA CC NIEHS NIDCD NCRR NINR NIBIB NCI FIC NIGRI NIGMS NCMHD 3 13 12 19 27 29 30 36 42 48 56 59 62 66 69 73 75 82 133 205 221 236 >300 Only Institutes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Conclusions • Page ranking is an important tool helping to assess the popularity and the quality of the website • Supercourse lectures are scored very highly by Google rankings • We need to explore how page rankings can influence information dissemination in the US and worldwide