Curve (maybe), Distribution NO.

Found on Flickr with the caption "Standard Normal Distribution".

Perhaps it is suggestive of histogram bars often seen with a bell-shape of a normal distribution. But what variable is being measured? See "NO, NO, NO, the Wrong Idea" in the previous post here.

NO, NO, NO. The wrong idea.

Found on Flickr here with the caption "normal distribution class photo".

A bell-shaped normal curve is not the normal distribution. The curve only describes the distribution. A normal distribution is a particular arrangement of measurements on a number line.

This photo seems to want to depict a normal distribution of the heights of students. If height is the variable of interest, the horizontal axis should be a number line with all the smallest students on the left and those taller would be placed further to the right. If the heights of the students had a bell-shaped histogram we would expect to see very few short students, very few tall students, and most of the students would have heights that fall between those extremes. This photo puts the tall students in the middle and shorter ones on the extremes. Maybe they have illustrated a bell-curve, but no number line is used, so no distribution (normal or otherwise) could be represented.

Just Marginal Joints

Here is a joint distribution of wear on the counter top of a Home Depot. The counter top was originally white. This has worn away to reveal various layers of shading in the laminate and further into the underlying wood of the table. The innermost area has been actually gouged out by many tools, cans of paint, and other heavy hardware. We see nested triangular patterns of wear revealing the joint distribution of tool placement on the counter and their movement across the checkout scanner.

But wait. There's more, as they say on infomercials. Not only do we get the joint distribution of wear, we also get one marginal distribution of wear along the front edge of the counter. As customers drag their purchases onto or off of the counter they leave a bell-shaped pattern of use along that front edge.

Our Video

Award for Best Evidence of Inspiring Students at the 2011 Joint Statistical Meetings in Miami Beach. Double click on video for full screen.

YADDA: Yet Another Door Distribution Again

This is an edge-on view of an open door. Notice the wear pattern along the edge. Another bell-shaped frequency distribution of wear.

Mc-Bell-Shaped

Wear caused by hands (fingers?) holding a door? Perhaps left hand fingers in the PULL slot and thumbs wearing away on the door edge. More frequent wear near the middle and less above and below. We've seen this pattern before, like here. There will be more to come. This pattern is quite common. Find one for yourself and share.

Skyscraper Frequencies

A sculpture of a keyboard with the key's height proportional to its letter's frequency of use in English. Looks like a small city block full of skyscrapers. How would the block look different if the frequencies of use were in another language. Via Geekologie. Thanks to Laura.
I examined related frequency and language questions here.