Tuesday 10 September 2013

NoFollow: Do not give WUWT & Co. unintentional link love

The hubris at WUWT.
Do you remember the search engine AltaVista? One reason it was overrun by Google, was that Google presented the most popular homepages at the top. It did so by analysing who links to who. Homepages that receive many links are assumed to be more popular and get a better PageRank, especially when the links come from homepages with a high PageRank.

The idea behind this is that a link is a recommendation. However, this is not always the case. When I link to WUWT, it is just so that people can easily check that what I claim WUWT has written is really actually there. It is definitely not a recommendation to read that high-quality science blog. To the readers this will be clear, but Google's algorithm does not understand the text, it cannot distinguish popularity from notoriety.

This creates a moral dilemma. Do you link to a source of bad information or not? To resolve this dilemma, and make linking to notorious pages less problematic, Google has introduce a new HTML-tag:

<a href="" rel="nofollow">Some homepage</a>.

If you add NoFollow to a link, Google will not follow the link and not interpret the link as a recommendation in its PageRank computation.

Skeptical sunlight

We are not the only ones with this problem. Many scientifically minded people have this problem, especially people from skeptical societies. Note, that here the word skeptical is used in the original meaning. From them I have this beautiful quote:
As Louis Brandeis famously said, "sunlight is the best disinfectant". Linking directly to misinformation on the web and explaining why it is wrong is like skeptical sunlight. ...

I think the correct way to proceed is to continue providing skeptical sunlight through direct linking. For one thing this demonstrates that we are not afraid of those who we oppose. In general they don’t link back to us, and that demonstrates something to casual readers who take note of it. ...

But while we are doing this we must be constantly vigilant of the page rank issue. Page ranking in Google is vitally important to those who are pushing misinformation on the web. It is how they attract new customers to their vile schemes, whether they be psychics or astrologers or homeopaths or something else. Even if we as skeptics are providing only a miniscule fraction of a misinformation peddler’s page rank, that fraction is too much.
Our links are probably the smallest part, but they may be important nonetheless. These links connect the climate ostrich pages with the main stream. Without our links, their network may look a lot more isolated. This is also important, PageRank is not just about links, but about links from authoritative sources.

If you search in Google using:


You will find many pages linking to WUWT that most likely do not want to promote the disinformation, on the contrary.


If you are a normal blog reader and make a comment once in a while, you likely do not have to do anything. Most blogs set links in comments automatically to NoFollow. This is done because spammers started writing spam-comments to make their homepages look more popular.

There are some blogs that want to reward readers making comments by giving them some link love back. Thus some blog comments are set to DoFollow. This is typically advertised.

Also when making comments in forums, where you have to log in to write your comments, it may be possible that the links are DoFollow by default. You can have a look by selecting the text around a link, click on your right mouse button to get to the context menu and then select view selection source. If this is the case, you will have to add rel="NoFollow" yourself.

If you are twittering, you should have no problem. The twitter.com homepage adds a nofollow statement. If you insert a tweet on your blog, you will have to add a NoFollow yourself, however.

Blog posts and webpages

For people with blogs and homepages, there is more work to do. You probably have to set all the unintended DoFollow links in your posts and webpages to NoFollow.

Doing this for many pages is work. There are some tools to help you. If you have a Wordpress blog, there is a plugin for you: nofollowr. It shows the blog administrator the status of every link and in addition allows for switching this status on and off.

For the others there are add-ons for Firefox that shows whether a link is NoFollow or DoFollow. This makes it easier to spot problems. This add-on worked fine for me. There is a similar add-on for Google chrome,Opera and Safari Browsers.

It is a bit of work and less fun as writing a new post, but well worth it.

What does not help is solve the problem by using URL shortening services such as TinyURL to indirectly link to the site they are debunking. Google still follows these redirects and still includes them in page rank calculations.

I have noticed that HotWhopper uses archive.is to link to WUWT. The links on these archives also link to WUWT, but do so with a NoFollow. So that should work as intended.

Another solution is not to link to WUWT, but to link to a science post discussing the WUWT post. This may be a good idea anyway; in Wikipedia there is a rule that secondary sources are preferred over primary sources. They are preferred because the add interpretation. Many primary sources and especially deception ones need interpretation.

You could find such secondary posts at: Wotts Up With That Blog, Hotwhopper, Wott's Up With That?, What's Up With That Watts?, VVatts Up With That. They regularly explain WUWT's errors. General climate sites that are regularly have to correct WUWT madness are: Open Mind, RealClimate, ThinkClimate and SkepticalScience.

* Hubris. Photo of Daedalus and Icarus found on Wikipedia is in public domain.


  1. Do you really think you can dry out WUWT like that?

  2. Welcome Doug. First of all, this is not my main intent. I just want people to be aware that their behaviour may have unintended consequences. I guess not everyone realises the consequences of the way Google search works. (And nowadays the other search engines as well.)

    Secondly, yes I could imagine that it would have some impact. Google not only looks at the number of incoming links, but also tries to estimate their reputation. Thus the links from pro-climate-science blogs may well be quite valuable. There will likely be much more links from climate ostrich blogs, but they may not count that much. The main problem would be the links from main stream media reporting on the view of the ostriches. I do not expect that many journalists would set their links to NoFollow.

    It won't be a big jump downwards, but it might help the start of a gradual trend downwards.

  3. Another thing to consider, especially if you are a working scientist with some reputation in the community, is that referring to disreputable sources may reflect negatively back at you.

    It's the same argument that (IIRC) Martin Reed used for refusing to debate some crank: "It will look good on your CV. On mine... not so much."

  4. @Martin Vermeer. You could be right. I already expect that even without discussing the climate ostriches blogging does not help my career.

    My posts on WUWT and Co. are harmful without doubt. No matter how well founded they are. They make me look less objective. Some of the dirt will always stick.

    Up to now I mainly do methodological stuff, but hopefully I will soon also do some analysis of real data. If it turns out that my work would suggest stronger trends, I am sure the climate ostriches will use previous posts about them against me.

    But well, someone should tell the younger generation that life it not just something you put on your CV. You only got one and better do something with it.

  5. > life it not just something you put on your CV. You only got one and better do something with it.

    Oh yes! Could be the story of my life...

    and BTW that was Sir Martin Rees.

  6. What exactly are you afraid of? If you believe in what you are doing do not try to stifle criticism. It is not scientific and will bite you in the backside if you are wrong, Mostly because a rethink and re-evaluation of your position by yourself will be less than welcomed because of your ( not to be questioned stance). However if you are so sure and confident in your position so be it.

  7. Anonymous, I am "afraid" that not everyone knows that by criticizing a blog post, you can actually unintentionally promote this blog post.

    I love scientific debate. That is the reason I became scientist.

    Unfortunately you implicit assume that the climate ostriches are part of a scientific debate is wrong. The average WUWT post is full of long debunked nonsense and misinformation. As such it only wastes peoples times and therewith makes a reasoned debate more difficult.

    We will continue understanding the climate system better and better. In other words, we will find errors in our current understanding. That is reason for joy, those are the moments for which you have become scientist, I would not call that being biting in the backside.

    After reading WUWT once in a while the last 2 years, I am sure that such improvements in our understanding will come from scientists and not from WUWT and co.

    Unfortunately, the misinformation at WUWT is not obvious in every case for everyone. Thus I would hate sending innocent people there without having read here what the mistakes are.

    If you think my contribution to the climate debate is not valuable, feel free to add NoFollow to your links to me. Just as the creationists do not link much to evolution blogs, I expect that that will not make much of a difference in my link popularity. Even if, so what.


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