A different way to classify LEGO elements

[62Bricks]

The current method of classifying LEGO elements used by Bricklink, LDraw, Peeron, etc. is based first on an element's shape and appearance (brick, plate, tile, round, etc.) and then on its other characteristics (modified, decorated, modified AND decorated, etc.) This has always struck me as awkward as it does not reflect the natural way one would probably classify elements when actually sorting them. For example, I have a storage container where I sort elements with clips. This container has sections for 1x1 clips (tile, modified), 1x1 and 1x2 bricks with clips (brick, modified) and 1x1 plates with clips (plate, modified). I also sort the elements with handles into that container because to me it makes sense to have commonly-connected pieces together. I imagine most builders naturally do something similar and arrange specialized elements by how they are connected.

I know the subject of sorting has been discussed extensively here, but rather than talking about the actual sorting I'm interested in talking about how we might come up with a classification system that is based on function rather than form. I think since the function of a LEGO element is to connect to another LEGO element, its connection type is its function. In this function-based system, the clip plates and clip bricks would all be in the same classification as they all have at least one knob, one tube, and one clip. Functionally, they are identical. The 1x1 clip (considered a "tile" in the form-based system) would be in a slightly different category, as it has a clip and a tube, but no knob. A flag, as another example, has only clips.

This kind of system would perhaps not be heirarchical, but more nebulous. As a first step, it would need a standard nomenclature for the types of connections LEGO elements can make. Off the top of my head, I come up with:

Knob

Tube

Bar

Clip

Bar hole

Pin

Pin w/friction

Pin hole

Pin Axle

Pin Axle Hole

Cross Axle

Cross Axle Hole

Ball

Socket

And of course all the types of hinges out there and probably a dozen more I'd come up with if I thought longer.

Has anyone already done this? I imagine TLG has "official" names for the connections. Does anyone know of a list that exists somewhere?

[Lego Otaku]

Everyone can sort LEGO in any ways that best suits them, there was never a rule on how it should be sorted. Some sort only byu color which can work fine for small lots. I usually sort them by Bricklink because I frequently buy and sell on BL and it's often easier for me to find what I want if I sorted the same.

[62Bricks]

Everyone can sort LEGO in any ways that best suits them, there was never a rule on how it should be sorted. Some sort only byu color which can work fine for small lots. I usually sort them by Bricklink because I frequently buy and sell on BL and it's often easier for me to find what I want if I sorted the same.

You're right, and people who build castles are going to sort their elements differently than people who build Technic mechanisms. I'm not talking about rules for sorting, but rather a more natural way to classify the elements by function rather than form. As it is now, if you are unfamiliar with the exceptions in the current system it is sometimes very difficult to guess what category a piece is classified in. Why is a 1x1 clip a modified tile and not a modified plate? Because neither category is really correct so they just had to choose one. A function-based classification system would let you find the piece knowing only what you can observe about the piece itself without having to know about the dozens of oddball parts that don't really fit into the form-based classifications.

[LEGO Historian]

You're right, and people who build castles are going to sort their elements differently than people who build Technic mechanisms. I'm not talking about rules for sorting, but rather a more natural way to classify the elements by function rather than form. As it is now, if you are unfamiliar with the exceptions in the current system it is sometimes very difficult to guess what category a piece is classified in. Why is a 1x1 clip a modified tile and not a modified plate? Because neither category is really correct so they just had to choose one. A function-based classification system would let you find the piece knowing only what you can observe about the piece itself without having to know about the dozens of oddball parts that don't really fit into the form-based classifications.

The problem with describing things based on their function, is because with using so much SNOT (studs-not-on-top) techniques today in many LEGO sets, that many items have many functions. This is true even without SNOT usage. For example, so many of the Modular sets have parts used in ways that most of us would not have envisioned... such as the lower 2x2 part of a 2x2 turntable can be used as a building architectural embellishment for an English Tudor half-timbering effect.

Also... the descriptions of parts aren't always apparent at first... such as your 1x1 clup example. Since that clip has no studs on top... it is not considered a modified plate... but instead a modified tile. It would be a 1x1 tile with a clip "modification" protruding from the top of the element. All modified plates have at least a stud somewhere on the top of the element... while modified tiles do not. Even the 1x2 jumper plate... while I have always assumed that it was a tile. But the fact that it is a tile with a central stud... changes the characteristic of it to be a plate... since all modified plates have studs somewhere on the element.

Also, interestingly enough we don't always use the same nomenclature as TLG does. One example is "sloped bricks". TLG often calls these "roof tiles". But this name is foreign to so many AFOLs. That may partly be because the in some countries real roof tiles are hardened terra cotta physical tiles... in other countries they are dark slate slabs, some countries they are light colored stone slabs or even thatch... and yet again in other countries they are bendable tar material. So calling them tiles seems foreign to so many of us... while the term "slopes" has a more universal appeal.

Edited December 26, 2013 by LEGO Historian

[62Bricks]

The problem with describing things based on their function, is because with using so much SNOT (studs-not-on-top) techniques today in many LEGO sets, that many items have many functions. This is true even without SNOT usage. For example, so many of the Modular sets have parts used in ways that most of us would not have envisioned... such as the lower 2x2 part of a 2x2 turntable can be used as a building architectural embellishment for an English Tudor half-timbering effect.

By "function" I'm just thinking of the ways a piece can ("legally") connect to other pieces, not the effect it is used for. Using a turntable base as an architectural element still uses the same knob and tube connection as attaching a 2x2 plate.

Also... the descriptions of parts aren't always apparent at first... such as your 1x1 clip example. Since that clip has no studs on top... it is not considered a modified plate... but instead a modified tile. It would be a 1x1 tile with a clip "modification" protruding from the top of the element.

I can follow your reasoning, and perhaps this is the thought process that led to it being called a modified tile, but a little more thought shows that this is really just arbitrary. The piece is not "modified" from anything else. It does not begin life as a smooth tile and then have a clip attached. Neither does it start life as a 1x1 plate and have its stud replaced with a clip. The underside of the element is identical to both the 1x1 tile and the 1x1 plate. It's neither a tile nor a plate, but because there is no ready class for such a beast it arbitrarily gets classed as a tile - and not because it has no stud. I wish the "All modified plates have at least a stud somewhere on the top of the element... while modified tiles do not" rule was consistently true, but alas is a Tile, Modified 4x4 with Studs on Edge. In fact, 11 of the 25 elements on Bricklink under "Tile, Modified" have studs on the top. There seems to be no real rule about what makes a plate a plate and a tile a tile. A jumper plate could just as easily fit into Bricklink's modified tile category as its modified plate category.

But if instead of trying to classify these pieces as either plates or tiles we had a system that classified them by the types of connections they could make, we wouldn't have that problem. The jumper plate would be, say, a piece with one top stud and two bottom tubes (that is, two places on the bottom where a stud can fit).

[AndyC]

By "function" I'm just thinking of the ways a piece can ("legally") connect to other pieces, not the effect it is used for. Using a turntable base as an architectural element still uses the same knob and tube connection as attaching a 2x2 plate.

Oddly enough that's one of the counter examples with attempting to classify solely by function being easier that sprang instantly to mind. Because what's the difference between a 2x2 plate and a 2x2 turntable if you consider only the connection points? Sooner or later you find yourself coming up with the equivalents of "tile, modified" to try and describe pieces anyway because the sheer variety of pieces with very similar connection points makes them difficult to differentiate between.

[Boxerlego]

I know the subject of sorting has been discussed extensively here, but rather than talking about the actual sorting I'm interested in talking about how we might come up with a classification system that is based on function rather than form. I think since the function of a LEGO element is to connect to another LEGO element, its connection type is its function. In this function-based system, the clip plates and clip bricks would all be in the same classification as they all have at least one knob, one tube, and one clip. Functionally, they are identical.

Has anyone already done this?

I do something similar. I sorting my parts based on function and size. For instance I have two bags full of gears, one bag has the all large gears and differentials and the other bag has the smaller gears and transmission parts. I do the same thing with my axles too. However sorting Lego bricks from Technic bricks is a little more complicated here and one thing I don't do is sort my parts based on that fact if it is studded or not.

[62Bricks]

Oddly enough that's one of the counter examples with attempting to classify solely by function being easier that sprang instantly to mind. Because what's the difference between a 2x2 plate and a 2x2 turntable if you consider only the connection points? Sooner or later you find yourself coming up with the equivalents of "tile, modified" to try and describe pieces anyway because the sheer variety of pieces with very similar connection points makes them difficult to differentiate between.

This is true. If the system only considers the type of connections possible, it would not distinguish between a 2x2 plate and a 2x2 turntable. But it would put them in the same category side by side where you could distinguish them visually. Or perhaps a connection that allows free movement is a type itself, which would distinguish them.

[62Bricks]

Thinking only of bricks and plates for the moment, they are currently distinguished by their height; A plate is one-third the height of a brick. But the height of a piece has no effect on how it can connect to another piece. In the context of a larger construction, of course, it makes a difference because a piece of a certain height may not align with other pieces. But considering only the types of connections they can make, a solid 2x4 brick is identical in function to a solid 2x4 plate.

But is a 2x4 brick identical in function to a 2x2 brick? They each have just knobs and tubes to make connections with. But they have a different number of possible connection points. The 2x4 brick has 8 knobs and 8 tubes. The 2x2 brick has 4 knobs and 4 tubes.

So functionally a 2x4 brick really has more in common with a 2x4 plate than it does with a 2x2 brick, yet the current system puts them in completely different categories.

[LEGO Historian]

Your tube count is off.... for 2x bricks the formula is......... (STUD COUNT / 2) - 1 = TUBE COUNT

[62Bricks]

Your tube count is off.... for 2x bricks the formula is......... (STUD COUNT / 2) - 1 = TUBE COUNT

You're right - I'm not using the term "tube" correctly - I mean the number of places a stud can connect. What is the accepted term? I've seen "anti-stud" used.

[62Bricks]

Here's an example of how you might use connectivity to define a class of LEGO elements:

There are many pieces we usually think of as "finishing" pieces - these are pieces used to create a "finished" look to a model.

Tiles are probably the most common kind of finish pieces. They are often used to cover up studs.

Cheese slopes are another common type of finish piece - similar to a tile, but sloped.

Various other pieces are also common finish pieces such as piece 88930:

and 6191:

Now Bricklink calls the upper piece a Curved Slope and the lower piece a Modified Brick even though they are essentially the same piece with different dimensions. This is kind of inconsistency that runs throughout the "standard" classification system (Bricklink seems to have inherited this particular oddity from LDraw/Peeron).

A system based on how pieces connect, however, might put a "tile" a "cheese slope" and these two pieces in the same group by noting that these pieces have only one type of connection. They can connect to other pieces in only one way. An inverted tile would also fall into this class:

Inexplicably, Bricklink put this fairly recent piece into the "Tile, Modified" category. It could just as easily be considered a modified plate, or even just a plain tile. This is only one of the problems that the current system creates. There has to be a better way to group pieces based on what you can observe intrinsically about the piece itself and not based on external, arbitrary knowledge.

[splatman]

The inverted tile, I would call "Tile, Inverted". After all, there is "Slope, Inverted", so it would make sense.

The cheese slope, I personally consider a Sloped Tile, being 1/2-way between a tile and a slope. It's smooth (slopes are textured), has rounded edges (slopes have square edges, like bricks) and has the prying groove (slopes do not), so, that seems to put the cheese in a sort of a middle ground. That said, it could just as well have been classed as a "Tile, Modified".

[62Bricks]

You're right about the cheese slope, it has characteristics of both the Tile and Slope categories. But in the current system, these pieces that are halfway between categories get put in one or the other with no consistent criteria.

Texture is an interesting characteristic. Many slopes are textured but not all. There are other textured pieces, too, like the log pieces, the grille tiles, the 1x2 bricks with the masonry pattern and the bricks with the grille texture. Bricklink calls these textured pieces "modified". Slopes with texture are not considered "modified" however. This is probably because almost all straight-angled slopes are textured. To a person unfamiliar with this external information this is potentially confusing - a texture is sometimes a modification and sometimes not.

[62Bricks]

Another potentially confusing "standard" that Bricklink uses is in expressing the dimensions of pieces. For bricks and plates, the shorter dimension is given first - a 2x4 brick, for example. It is different for slopes, however, where the sloped dimension is given first - This is a 4x2 slope, for example:

One the one hand, this convention might have been thought useful as it indicates the direction of the slope, but on the other hand it breaks the convention used for almost every other type of piece. Bricklink's general philosophy seems to assume a core type of piece, then call extended or variant versions of that piece "modified." Rather than consider slopes "modified" bricks, however, it has made them a core piece type with its own scheme for expressing dimensions.

[LEGO Historian]

.... actually 62Bricks... Bricklink tries to stay to the W x L x H nomenclature... but not all items have all 3 dimensions listed. Therein lies part of the confusion.

The 4x2 (x1) slope has a width of 4, a length of 2 and an implied height of 1. A 45 degree sloped brick with 2x4 follows this same design... thus making the 4x2 slope with a width of 2, a length of 4, and an implied height of 1.

The problem here gets to be when you have plates and tiles that are only 1/3 (or other) heights. So they would be 2x4 (x 1/3). Getting a universal measurement becomes problematic due to this (and other) reasons.

But yes... first time users of Bricklink, and Peeron, do have a learning curve to overcome when using LEGO measurements.

However... I'm not sure that there's a better way to overcome this problem....

[62Bricks]

.... actually 62Bricks... Bricklink tries to stay to the W x L x H nomenclature... but not all items have all 3 dimensions listed. Therein lies part of the confusion.

The 4x2 (x1) slope has a width of 4, a length of 2 and an implied height of 1. A 45 degree sloped brick with 2x4 follows this same design... thus making the 4x2 slope with a width of 2, a length of 4, and an implied height of 1.

...

This is what I'm saying - rather than considering slopes as modified bricks and measuring them in the same way, Bricklink (and Peeron/Ldraw, for the most part, before it), uses the size of the slope to define the dimensions of the piece.

But really there is no logic behind this, it's just an arbitrary convention. If you take a 2x4 brick and rotate it 90 degrees it does not become a 4x2 brick. Its dimensions are the same. A consistent system should categorize all pieces that have the same footprint - 2 studs in one direction and 4 studs in the other - as having the same width and length dimensions. The 45-degree 2x4 slope piece has the same dimensions as an 18-degree 4x2 slope piece.

Information about the slope is already given in the naming convention (18-degree, 33-degree, 45-degree, etc.). There's no need to alter the WxLxH convention just for slopes. This oddity becomes especially apparent when using a parts database. Computers need consistency to put things in proper order.

Ironically, it may be computers that led to this weirdness in the first place. I'm not sure, but I expect that measuring slopes this way came from LDraw, where the .dat files give pieces a default X,Y,Z orientation.

[edited to add:] I see that TLG, although also inconsistent, uses the same method to measure slopes as it does to measure bricks. Thus is a "roof tile, 2x4x1, 18-degrees"

Edited December 31, 2013 by 62Bricks

[62Bricks]

One reason I'm kind of obsessed with this question of classification right now is because of the news that Bricklink is asserting its control over its own method of naming, numbering and classifying parts. Its intention, of course, is to prevent commercial competitors from piggybacking on its database. I think most people can understand why they would want to do that, but the result is that other sites - even sites that do not compete directly with Bricklink, like Rebrickable - are severing all ties with Bricklink and using information from other sources.

So I think over time we are going to see a wider divergence in how parts are classified and named. Bricklink has a lot of influence because it is the oldest and largest of the secondary market sites. It remains to be seen how tight a hold they will keep on the use of their classification system, or what other sites they might go after for using it. The example set by TLG is wonderful - essentially, as long as you do not create any confusion about whether you are actually representing TLG officially, you are free to share images, information, instruction scans, etc. It is this kind of openness that allowed Bricklink to even exist in the first place.

I'm not going to condemn Bricklink for its decision, but I think it's an opportune moment for the LEGO community to be taking a look at the collective work that has already been done creating a system that describes the domain of LEGO elements. It needs improvement and greater consistency, and there are tools available now that were not available 15-20 years ago when we came online. If Bricklink wants to keep its system all for itself, I say let them have it. It's riddled with inconsistencies and illogical classifications.