Jonathan Huang, Jane Manning, Marc Sanders
In an earlier blog post, Manning and Sanders looked at the prevalence of forum posting relative to performance in a collection of Stanford MOOCs offered through Coursera. The blog left some readers curious about how forum posting varied with other demographics such as age and gender of participants. For instance, how old are the participants who post the most? How old are those who post the least? Is gender correlated with posting habits? A quick run of the numbers gave some unexpected results—at least they were unexpected to us. When it comes to posting on MOOC forums, Gen-X/Y/Z-ers take a back seat to Baby Boomers.
The data we used for demographic information came from a survey distributed via email to participants in Coursera courses. Among the classes we looked at in this round (32 classes, with a total of ~1.5M enrollments from ~900K student accounts), 11.7% of students filled in the survey, and students who filled in the survey were somewhat more inclined to post than the student population overall: 6.5% vs 4%. (Note that we ignored posts in the first week of the course because so many of those posts were personal introductions, and we counted “comments” as posts, just like new threads or replies.) We partitioned the respondents into 5-year age ranges starting at 15, where range “M-N” denotes those who are at least M years old but not yet N years old. Here are the number of respondents in each age range and gender:
|age range||# male||# female|
The largest groups were those of ages 25-30, 20-25, and 30-35. This wasn’t surprising, and–given their relative comfort and experience with these mediums–we expected those groups to be the ones who tended to post the most as well. But this isn’t what we saw.
First, here’s how things broke down by age:
Surprised? What is a plausible explanation for the trend? We wondered whether it might be that retirees have more free time (and perhaps untapped social energy). That may be true but how do we account for the difference between the posting of 20- and 30-somethings and those of us lucky enough to be middle aged?
One way to begin the investigation is to partition the respondents into two groups, which we’ll call “Full-time Committed” (FTC) and “Non Full-time Committed” (NFTC). FTCs are those who are either full-time employed, full-time student, or are both part-time student and part-time employed. The NFTC consist of everyone else–e.g., retirees, homemakers, unemployed, part-time students, etc. Is the distribution of NFTCs across the age ranges similar to the distribution of percent posters across those ranges? Roughly, yes: we’ve seen that as age increases, so does posting, and (not surprisingly) so does percent of NFTC:
In total, while only 6% of the FTCs posted, 10% of the NFTCs did so. Moreover, there were .39 posts per FTC respondent but .90 posts per NFTC respondent. This strongly suggests that having more free time is conducive to posting more. And, it turns out, there’s more to the story. Let’s consider in each age range the percentage of FTCs and NFTCs who posted:
While it’s true that in every age range except the last the NFTCs are more likely posters than the FTCs, the percent of FTC posters still increases with age. Additionally, the FTCs in all age ranges 50+ still are more likely to be posters than the NFTCs in age ranges below 40. For instance, FTCs of age 50-55 are more likely to post than NFTCs between 35 and 40. So NFTCs might have more time to post, and they do post more, but according to this data there are still other independent age-related factors at play.
Now let’s turn briefly to gender. Should we expect to see non-trivial differences in posting frequency between men and women? It turns out that while women after age 30 are more likely posters than men, the difference is typically no more than three percentage points…except for one age range where the difference is quite noticeable.
What could account for the high rates of posting by women aged 65-70? The %NFTCs for women in this age range is no larger than for men. So, it’s not that simple. And why the 5-year drop in posting for women turning 50?
We hope you’ll share your thoughts by leaving a comment. We look forward to your explanations, and if the data allows us to test your hypotheses, we’ll try to do that, and we’ll report back!