All Eyes on Facebook

A recent social media report from Nielsen’s shows, amongst other things, that Facebook dominates our attention on the Internet, larger in terms of minutes of face time than the four next most popular social media sites. Business Insider produced the following chart based on Nielsen’s data

It was recently (and widely) reported that the number of page views on Facebook passed the 1 trillion mark, but that figure has been disputed. In any case, all internet path seems to lead to Facebook one way or the other.

The “Half-life” of a bitly link is about 3 hours

Hilary Mason, Chief Scientist at bit.ly, a large link shortening service, has done an analysis on some of their link data to get an idea of how long links remain “alive” or “popular”. The measure was to look at 1,000 links and graph the number of hits that a link receives over 80,000 seconds (almost a day), and then determine the point over that period where half of the total number of hits were received. From the post

So we looked at the half life of 1,000 popular bitly links and the results were surprisingly similar. The mean half life of a link on twitter is 2.8 hours, on facebook it’s 3.2 hours and via ‘direct’ sources (like email or IM clients) it’s 3.4 hours. So you can expect, on average, an extra 24 minutes of attention if you post on facebook than if you post on twitter.

Running the data yielded the following graph, showing a strong power law for Facebook, Twitter and direct links (links shared via email, and instant messengers), but a delayed curve for YouTube.

What Mason computed would more accurately be called the median rather than the half-life, since she is interested in the first point in time that divides the total number of hits for the period into two roughly equal sets. More discussion on this point is given in the comments to the post. The conclusion from the post

In general, the half life of a bitly link is about 3 hours, unless you publish your links on youtube, where you can expect about 7 hours worth of attention. Many links last a lot less than 2 hours; other more sticky links last longer than 11 hours over all the referrers. This leads us to believe that the lifespan of your link is connected more to what content it points to than on where you post it: on the social web it’s all about what you share, not where you share it!

A while back I posted on the half-life of patching vulnerabilities being 30 days and there we probably have confusion with the sample median as well. I also noted the attrition for my own links in Shark Fin posts.

US Grade Inflation Study

A recent study has examined the prevalence of grade inflation at US universities over the last 100 years or so, and has found some identifiable patterns. The chart below shows the increase in grades between various types of schools in the primary colors, with the grey representing (unnamed individual schools).

What is clear is that there was a huge increase in grade in crease in the 60’s and then a steady increase over  the last 30 years of so. From the study

The rise in grades in the 1960s correlates with the social upheavals of the Vietnam War. It was followed by a decade
period of static to falling grades. The cause of the renewal of grade inflation, which began in the 1980s and has yet to
end, is subject to debate, but it is difficult to ascribe this rise in grades to increases in student achievement. Students’ entrance test scores have not increased (College Board, 2007), students are increasingly disengaged from their studies (Saenz et al., 2007), and the literacy of graduates has declined (Kutner et al., 2006). A likely influence is the emergence of the now common practice of requiring student-based evaluations of college teachers. Whatever the cause, colleges and universities are on average grading easier than ever before.

Further science and engineering students are graded more harshly than their fellow students in liberal arts degrees.