I always wondered why old movies are rated so high on IMDb. For example, 12 Angry Men (1954) with just ~900K votes ranks about as high as Inception (2010) with ~2M votes. Few people I know have seen 12 Angry Men. So where does this high rating come from? My theories were: Old movies really are that good. IMDb’s algorithm is biased towards old movies. People remember older movies fondly. Actually, it’s none of these. It’s selection bias. ...
A question from Dorai get me thinking: does being good at maths help in programming? I don’t have a personal view. But since Reportbee has data on the Class 12 examination results for the last three years, we thought we could do a bit of analysis. Here’s the correlation of the scores of various subjects with Computer Science. Correlation Subject 0.79 CHEMISTRY 0.79 PHYSICS 0.75 ENGLISH 0.75 MATHEMATICS 0.72 LANGUAGE 0.67 BIOLOGY 0.66 ECONOMICS 0.66 COMMERCE 0.65 ACCOUNTANCY 0.56 HISTORY 0.52 GEOGRAPHY It almost breaks neatly into four groups. ...
Does it matter which month you’re born in? Based on the results of the 20 lakh students taking the Class XII exams at Tamil Nadu over the last 3 years (via Reportbee), it appears that the month you were born in can make a difference of as much as 120 marks out of 1,200 – or 10%! Most students who took the Class XII exams in 2011 were born between March 1991 and June 1992. The average marks of each student (out of 1200) is shown in the graph below. ...
Sometimes, school marks are moderated. That is, the actual marks are adjusted to better reflect students' performances. For example, if an exam is very easy compared to another, you may want to scale down the marks on the easy exam to make it comparable. I was testing out the impact of moderation. In this video, I'll try and walk through the impact, visually, of using a simple scaling formula. BTW, this set of videos is intended for a very specific audience. You are not expected to understand this. ...
My earlier list of statistically improbable phrases in Calvin and Hobbes is technically just a list of “Statistically Improbable Words”. I re-did the same analysis using phrases. Here are the top 20 statistically improbable phrases (2 - 4 words only): baby sitter chocolate frosted sugar bombs comic books doing homework fearless spaceman spiff() good night hamster huey ice cream miss wormwood new year peanut butter really think slimy girls spaceman spiff stuffed tiger stupendous man sugar bombs susie derkins watch tv water balloon That is, these are the 2-4 word phrases whose frequency in Calvin and Hobbes is substantially (at least 5 times) higher than in the other books I have. ...
14 years ago, I was introduced to the process of normalising grades. Professors “fit” students’ marks into a normal distribution and assign grades based on that. (I still don’t know how they do it). Since then, I’ve encountered normalising a lot. My performance at work is normalised. I normalise my song ratings and movie ratings. I’ve normalised all kinds of things at work: lead-time of delivery of fans, movements in savings account balances, calls to a call centre, demand for a resource… you name it. ...
Gap Minder – an excellent dynamic interface to world economic indicators.
Benford’s Law: how to spot fake data.
Google India Zeitgeist.
Interesting statistics on pizza purchases and tips.
Coincidences are common.
I win the bet. ~sanand strikes 14340 to 2931 versus ~mkalidas. Must admit that some people disagree with the majority, though.