A Statistical Evaluation of the Work of Bob Ross

Bob Ross was a consummate trainer. He guided followers alongside as he painted “glad bushes,” “almighty mountains” and “fluffy clouds” over the course of his 11-year tv profession on his PBS present, “The Pleasure of Portray.” In whole, Ross painted 381 works on the present, counting on a definite set of parts, scenes and themes, and thereby offering hundreds of information factors. I made a decision to make use of that information to show one thing myself: the necessary statistical ideas of conditional chance and clustering, in addition to a lesson on the restrictions of information.

So let’s perm out our hair and prepare to create some glad spreadsheets!

What I discovered — by way of information evaluation and an interview with one among Ross’s closest collaborators — was a physique of labor that was outlined by consistency and a essentially private ultimate. Ross was born in Daytona, Fla., and joined the Air Pressure at 17. He was stationed in Fairbanks and spent the following 20 years in Alaska. His time there appears to have had a big impression on his most popular topics of bushes, mountains, clouds, lakes and snow.

Of the 403 episodes of “The Pleasure of Portray” — whose first run was from 1983 to 1994 and which continues to air in reruns on PBS stations nationwide — Ross painted in 381, and the remainder featured a visitor, most often his son Steve Ross. Primarily based on pictures of Bob Ross’s work accessible within the Bob Ross Inc. retailer, I coded all of the episodes utilizing 67 key phrases describing content material (bushes, water, mountains, climate parts and man-made buildings), stylistic selections in framing the work, and visitor artists, for a grand whole of three,224 tags.

I analyzed the info to seek out out precisely what Ross, who died in 1995, painted for greater than a decade on TV. The highest-line outcomes are to be anticipated — wouldn’t , he did paint a bunch of mountains, bushes and lakes! — however then I put some numbers to Ross’s traditional figures of speech. He didn’t paint oaks or spruces, he painted “glad bushes.” He favored “almighty mountains” to peaks. As soon as he’d painted one tree, he didn’t paint one other — he painted a “good friend.”

Right here’s how usually every tag that appeared greater than 5 occasions confirmed up over the 381 episodes:

Now that we all know the essential possibilities of particular person tags, we will additionally discover the joint possibilities of a few of these occasions. As an example, how usually do a deciduous tree and a coniferous tree seem in the identical portray? We all know that 57 % of work comprise a deciduous tree and 53 % of work comprise a coniferous tree. In accordance with our information set, 20 % of work comprise not less than one among every.

What’s extra, we will additionally discover the chance that Ross painted one thing provided that he painted one thing else, a statistic that’s referred to as conditional chance.

Conditional chance generally is a bit difficult. We all know that 44 % of Ross’s work comprise clouds, 9 % comprise the seaside and seven % comprise each the clouds and the seaside. We will use this data to determine two issues: the chance that Ross painted a cloud given that he painted a seaside, and the chance that he painted a seaside given that he painted a cloud. You divide the joint chance — 7 % on this case — by the chance of the given — 44 % or 9 %, relying on whether or not you wish to know the chance of a seaside given a cloud or a cloud given a seaside.

The most important pitfall folks usually face is assuming the 2 possibilities are the identical. The chance that Ross painted a cloud provided that he painted the seaside — basically, what number of seaside work have clouds — is (0.07)/(0.09), which is 78 %. The overwhelming majority of seaside scenes comprise clouds. Nevertheless, the chance that Ross painted a seaside provided that he painted a cloud — or, what number of cloud work comprise a seaside — is (0.07)/(0.44), or 16 %. So the overwhelming majority of cloud work don’t have seashores.

I discovered the conditional chance of each Bob Ross tag in opposition to each different tag to reply the next urgent questions.

What’s the chance, provided that Ross painted a contented tree, that he then painted a good friend for that tree?

There’s a 93 % likelihood that Ross paints a second tree provided that he has painted a primary.

What share of Bob Ross work comprise an almighty mountain?

About 39 % prominently characteristic a mountain.

What share of these work comprise a number of almighty mountains?

Ross was additionally amenable to portray pals for mountains. Sixty % of work with one mountain in them have not less than two mountains.

In what share of these work is a mountain lined with snow?

Provided that Ross painted a mountain, there’s a 66 % likelihood there’s snow on it.

What about footy little hills?

Hills seem in 4 % of Ross’s work. He clearly most popular almighty mountains.

How about glad little clouds?

Wonderful query, as 44 % of Ross’s work prominently characteristic not less than one cloud. Given that there’s a painted cloud, there’s a 47 % likelihood it’s a distinctly cumulus one. There’s solely a 14 % likelihood {that a} painted cloud is a distinctly cirrus one.

What about charming little cabins?

About 18 % of his work characteristic a cabin. Provided that Ross painted a cabin, there’s a 35 % likelihood that it’s on a lake, and a 40 % likelihood there’s snow on the bottom. Whereas 72 % of cabins are in the identical portray as conifers, solely 63 % are close to deciduous bushes.

How usually did he paint water?

On a regular basis! About 34 % of Ross’s work comprise a lake, 33 % comprise a river or stream, and 9 % comprise the ocean.

Appears like he didn’t just like the seaside.

A lot on the contrary. You’ll be able to see the seaside in 75 % of Ross’s seaside work, however the solar in solely 31 % of them. If there’s an ocean, it’s in all probability uneven: 97 % of ocean work have waves. Ross’s 36 ocean work have been additionally extra more likely to characteristic cliffs, clouds and rocks than the typical portray.

What about Steve Ross?

Steve appeared to favor lakes excess of Bob. Whereas solely 34 % of Bob’s work have a lake in them, 91 % of Steve’s work do.

One helpful lens we will apply to this type of information — the place we’re evaluating vectors of data — is a clustering software. The thought behind clustering is to find out how shut sure teams of information are to different factors within the information set. Researchers use clustering evaluation in all types of areas — from biology to shopper advertising — as a method of segmenting a inhabitants of, say, crops or folks. It permits us to seek out fascinating subsets of information based mostly on how related or totally different sure subgroups are from the remainder of the set.

I used an algorithm to divide the whole set of 403 work from “The Pleasure of Portray” into clusters of comparable work. I wished to know whether or not it was attainable to establish the ten primary work featured on the PBS collection. To do that, I ran a k-means clustering evaluation of the work. The outcomes have been combined.

First, let’s have a look at the clusters that make intuitive sense. The clear winners are:

• A cluster of fifty work tagged “snow” and “winter”
• A cluster of 28 work every with an oval white-space body
• A cluster of 35 work of ocean scenes.

These have been the sorts of clear clusterings we have been hoping to seek out. Every has a standard theme and falls below the banner of iconic Bob Ross pictures. He painted about one seaside scene and one oval-framed picture per season, and about two scenes with snow within the foreground per season. It is sensible.

Listed here are some clusters that additionally make sense, however don’t inform us a complete lot about Ross’s favourite form of portray:

• A cluster of 13 work by visitor host Steve Ross
• A cluster of seven work containing a bridge
• A cluster of 11 work containing flowers
• A cluster of 30 work containing a fence or a barn
• A cluster of 33 work containing a waterfall.

These clusters establish some tags that seem in just a few work, however the groupings aren’t supremely useful in defining what Ross painted. For instance, flowers have been very not often the primary focus of a portray, and we already knew what number of occasions Steve Ross appeared on this system.

The ultimate two clusters have been essentially the most broad:

• A cluster of 95 work that had bushes and not less than one mountain
• A cluster of 103 work that had bushes however no mountains.

Not supremely useful, however nonetheless fairly fascinating. Clustering evaluation is an interesting software for this sort of information however hardly has all of the solutions.

To study extra about Ross and his work past what I already knew from the info, I referred to as Annette Kowalski, who based Bob Ross Inc. with the painter and stays the steward of his work. She confirmed one thing I had found in my evaluate of a whole bunch of Ross’s landscapes: His work isn’t outlined by what’s included in his work, however by what’s excluded.

“I can consider two occasions he painted folks,” Kowalski stated. “There was a person by a campfire, and two folks strolling by way of the woods.” Certainly, our information reveals that Ross solely painted an individual — in silhouette in opposition to a tree close to a campfire — one time.

After we analyze the buildings he painted, it seems Ross most popular the easy to the flowery. He painted 69 cabins, 25 fences in varied states of disrepair and 17 barns. Extra advanced man-made buildings are remarkably uncommon in his work. Bridges seem solely seven occasions. Boats and mills, twice every. Ross painted one dock, one lighthouse and one windmill over his 381 episodes.

There’s one thing concerning the buildings Ross painted that has gone nearly completely unnoticed by followers, based on Kowalski.

“I’ll let you know Bob’s largest secret. If you happen to discover, his cabins by no means had chimneys on them,” she stated. “That’s as a result of chimneys represented folks, and he didn’t need any signal of an individual in his work. Test the cabins. They haven’t any chimneys.”

She instantly added, “I’m certain you’re going to name me tomorrow and say you discovered a chimney.” And I did! However it took a number of searching. In season 7 episode 1, “Winter Cabin,” there’s a chimney on the cabin (featured above within the third row, middle column). However the truth that a chimney appeared as soon as in 381 work doesn’t actually diminish Kowalski’s level.

When it comes all the way down to it, “The Pleasure of Portray” was by no means actually about portray. Even Kowalski, who runs an organization that sells Bob Ross-branded portray provides, believes most viewers aren’t in it for the artwork.

“The bulk of people that watch Bob Ross have little interest in portray,” she stated. “Principally it’s his calming voice.”