Can Alexa ratings/rankings be trusted?
tokenadult: Alexa users are a convenience sample, not a simple random sample, and they may badly misrepresent your user base. Essentially, installing Alexa (which I did once, but haven't done on my current browser) is something like participating in a voluntary response poll. One professor of statistics, who is a co-author of a highly regarded AP statistics textbook, has tried to popularize the phrase that "voluntary response data are worthless" to go along with the phrase "correlation does not imply causation." Other statistics teachers are gradually picking up this phrase.[quote=Paul Velleman]-----Original Message-----
From: Paul Velleman [SMTPfv2@cornell.edu]
Sent: Wednesday, January 14, 1998 5:10 PM
To: apstat-l@etc.bc.ca; Kim Robinson
Cc: mmbalach@mtu.edu
Subject: Re: qualtiative studySorry Kim, but it just aint so. Voluntary response data are worthless. One excellent example is the books by Shere Hite. She collected many responses from biased lists with voluntary response and drew conclusions that are roundly contradicted by all responsible studies. She claimed to be doing only qualitative work, but what she got was just plain garbage. Another famous example is the Literary Digest "poll". All you learn from voluntary response is what is said by those who choose to respond. Unless the respondents are a substantially large fraction of the population, they are very likely to be a biased -- possibly a very biased -- subset. Anecdotes tell you nothing at all about the state of the world. They can't be "used only as a description" because they describe nothing but themselves.[/quote]http://mathforum.org/kb/thread.jspa?threadID=194473&tsta...But to answer your underlying question, if I had good Alexa stats, I would talk them up. You may as well talk about the most convincing data you have, while acknowledging that the data may not be definitive.