Archive for February, 2009

Persistent Identifiers for Scientific Data Provenance

Monday, February 23rd, 2009

In this week’s ebiquity meeting (10:00am EDT Wed 2/25, ITE 325), Curt Tilmes will talk on “Persistent Identifiers for Earth Science Provenance“.

Historically, published scientific research could include a description of an experiment that an independent party could use to reproduce the experiment with the same results, confirming the research. Modern research in the field of earth science often depends on terrabytes of data captured from remote sensing instruments, complex computer algorithms that undergo numerous changes over the year. A single result could be the result of the work of hundreds of individuals over decades. The representation of the measurements, algorithms and all the other artifacts of experimentation leading to that result becomes a daunting problem. A key to handling this representation is a good scheme for persisent identifiers.

Persistent identifiers seem like a simple problem. Just make a good URL and don’t change it [1]. This sounds good in theory, but is difficult to maintain forever. Many other schemes have been proposed to attack various aspects of the problem of identification, with various advantages and disadvantages. I will introduce this topic and briefly describe some of the concerns with using identifiers specifically in the context described above, and some of the characteristics of various identifier schemes.

The presentation will be streamed live via ustream.tv

References and some identifier schemes

[1] Cool URIs Don’t Change
[2] Naming and Addressing: URIs, URLs, …
[3] Object Identifer (OID)
[4] The Digital Object Identifier (DOI) System
[5] Persistent Uniform Resource Locator
[6] A Universally Unique IDentifier (UUID) URN Namespace
[7] XRI (Extensible Resource Identifier)

Facebook backs down and reverts to old TOS policy

Wednesday, February 18th, 2009

Late last night Facebook CEO Mark Zuckerberg announced in a blog post, Update on Terms, that they have rolled back the recent changes to their Terms of Service agreement and restored the previous one.

“Many of us at Facebook spent most of today discussing how best to move forward. One approach would have been to quickly amend the new terms with new language to clarify our positions further. Another approach was simply to revert to our old terms while we begin working on our next version. As we thought through this, we reached out to respected organizations to get their input.

Going forward, we’ve decided to take a new approach towards developing our terms. We concluded that returning to our previous terms was the right thing for now. As I said yesterday, we think that a lot of the language in our terms is overly formal and protective so we don’t plan to leave it there for long.”

The NYT reported the change in a story today, Facebook Withdraws Changes in Data Use.

In his post, Zuckerberg continued by observing that with 175 million members, if it were a country, it would be the sixth most populated one in the world. Of course, sometimes a population revolts and lays claim to certain unalienable rights, among theme being life, liberty, pursuit of happiness and ownership of one’s online content.

So, the missing clause is back in the FB TOS:

“You may remove your User Content from the Site at any time. If you choose to remove your User Content, the license granted above will automatically expire, however you acknowledge that the Company may retain archived copies of your User Content.”

This revision is dated 23 September 2008. Curiously, I checked the Internet Archive to review the history of FB’s TOS but found that there are no archived copies after 12 October 2007. I can only imagine that FB asked the Internet Archive to stop saving copies of this public page. I note that the last archived copies of many of their public pages (e.g., privacy policy, developers page, etc.) are also from 2007. These pages are not blocked by the FB robots.txt and are normally accessible to anyone, so it must be by a specific request that they not be archived.

That’s too bad. Having an easy way to see how the policies of important social sites like FB evolve would be a great resource to those who study online social media as well as to many curious users.