Bongard Problems sorted left have the keyword "unwordable" on the OEBP.

"Unwordable" does not just mean convoluted, that is, involving a long description. "Unwordable" also does not just mean hard. Unwordable Bongard Problems are instead those Bongard Problems whose solutions tend to occur to people nonverbally before verbally. The typical "unwordable" Bongard Problem solution is not too difficult to see, and may be easy to describe vaguely, but hard to pin down in language.

The solution title given on the OEBP for "unwordable" pages is often something vague and evocative, further elaborated on in the comments. For example, the title for BP524 is "Same objects are shown lined up in both 'universes' vs. the two 'universes' are not aligned." If someone said this, it would be clear they had seen the answer, even though this is not a clear description.

Bongard Problems have been sorted here based on how hard they are to put into words in English. (See keyword culture.) It may be interesting to consider whether or not the same choices would be made with respect to other languages.

Adjacent-numbered pages:
BP501 BP502 BP503 BP504 BP505  *  BP507 BP508 BP509 BP510 BP511

notso, subjective, meta (see left/right), links, keyword, sideless

bp [smaller | same | bigger]

Aaron David Fairbanks

Left examples have the keyword "overriddensolution" on the OEBP.

An "overriddensolution" is solution idea for a Bongard Problem that would not be chosen by the solver because there is a simpler solution that always comes with it.

An overridden solution occurs when the Bongard Problem's examples on both sides all share some constraint, and furthermore within this constrained class of examples, the intended rule is equivalent to a simpler rule that can be understood without noticing the constraint. See e.g. BP1146. The solver of the Bongard Problem will get the solution before noticing the constraint.

There is a more extreme class of overridden solution: not only is the solution possible to overlook in favor of something simpler, but even with scrutiny it will likely never be recognized. See e.g. BP570. This happens when intended left and right side rules are not direct negations of one another, but one or both of these rules is not "narrow"-- it can only be communicated in a Bongard Problem by its opposite being on the other side.

TO DO: Should this more extreme version have its own keyword? - Aaron David Fairbanks, Nov 23 2021

The keyword left-narrow (resp. right-narrow) is for Bongard Problems whose left-side (resp. right-side) rule can be recognized alone without examples on the other side.

The keyword notso is for Bongard Problems whose two sides are direct negations of one another.

See keyword impossible for solution ideas that cannot even apply to any set of examples, much less be communicated as the best solution.

Adjacent-numbered pages:
BP563 BP564 BP565 BP566 BP567  *  BP569 BP570 BP571 BP572 BP573

BP570 "Shape outlines that aren't triangles vs. black shapes that aren't squares" was created as an example of this.

meta (see left/right), links, keyword

bp [smaller | same | bigger]

Aaron David Fairbanks

Adjacent-numbered pages:
BP686 BP687 BP688 BP689 BP690  *  BP692 BP693 BP694 BP695 BP696

meta (see left/right), links, metaconcept, primitive, left-it, feedback

bp [smaller | same | bigger]

Harry E. Foundalis

Left examples have the keyword "contributepairs" on the OEBP.

When this keyword is added to a Problem, OEBP users are advised to add a corresponding right example for every left example they add and vice versa.

It is common for Bongard Problems to present left examples on the left side and corresponding altered versions of those examples on the right side, tweaked only slightly, to highlight the difference and make the solution easier to see (see keyword help).

This is common in more abstract Bongard Problems that admit a wide range of examples, a variety of different styles or types (e.g. BP360). Showing two versions of the same thing, one on the left and one on the right, helps a person interpret what that thing is meant to be in the context of the Bongard Problem; whatever qualities vary between the two in the pair must be relevant.

If a person cannot sort an example according to the solution property without seeing its corresponding opposite example, the Bongard Problem is invalid (see https://www.oebp.org/invalid.php ). There is no one rule dividing the sides; the solution is not a method to determine whether an arbitrary example fits left or right. See also Bongard Problems with the keyword collective, which are similarly borderline-invalid.

A BP in which each left example corresponds to a right example and vice versa could be remade as a Bongard Problem in which the left examples are the pairs. For example BP360 would turn into "a pair consisting of the ordered version of something and the chaotic version of the same thing vs. a pair of things not satisfying this relationship." This process would turn a Bongard Problem that is invalid in the sense described above into a valid one.

(See keyword orderedpair.)

In some "contributepairs" Bongard Problems there really is a natural choice of left version for every right example and vice versa (see keyword dual); in others the choice is artificially imposed by the Bongard Problem creator.

When "contributepairs" Bongard Problems are laid out in the format with a grid of boxes on either side of a dividing line, the boxes may be arranged so as to highlight the correspondence: either

A B | A B

E F | E F

G H | G H

or

A B | B A

E F | F E

G H | H G.

Adjacent-numbered pages:
BP914 BP915 BP916 BP917 BP918  *  BP920 BP921 BP922 BP923 BP924

meta (see left/right), links, keyword, oebp, right-self, instruction

bppage [smaller | same | bigger]
zoom in left (correspondence_bp)

Aaron David Fairbanks

Left examples have the keyword "infodense" on the OEBP.

Consider the amount of data a person has to consciously unpack in each example in the process of determining how it should be sorted. In BP3, it is only necessary to notice the color of the shape. In BP871, however, it is important to read various qualities of every tiny shape shown.

Images of Bongard Problems that are "infodense" typically need to include a large number of examples in order to communicate the solution clearly without admitting unintended solutions. With so much data packed in each example, it becomes more likely that some of the random patterns in the data will happen to distinguish between the two sides in an unintended way. A similar issue appears in convoluted Bongard Problems.

Contrast "infodense" Problems to hardsort Bongard Problems, in which examples are difficult to sort, but perhaps that difficulty does not stem from reading a high amount of information; perhaps there is a small amount of information extracted from the examples, but it is hard to determine whether or not that information fits a rule.

Adjacent-numbered pages:
BP973 BP974 BP975 BP976 BP977  *  BP979 BP980 BP981 BP982 BP983

abstract, spectrum, meta (see left/right), links, keyword

Aaron David Fairbanks

Left examples have the keyword "funny" on the OEBP.

Adjacent-numbered pages:
BP995 BP996 BP997 BP998 BP999  *  BP1001 BP1002 BP1003 BP1004 BP1005

less, subjective, culture, meta (see left/right), links, keyword, left-self, left-it, feedback, funny

bp [smaller | same | bigger]

Aaron David Fairbanks

Left-sorted Bongard Problems have the keyword "rules" on the OEBP.

In the typical "rules" Bongard Problem, it is possible to come up with many convoluted rules that fit each example, but the intended interpretation is the only simple and obvious one.

Since it is difficult to communicate a rule with little detail, "rules" Bongard Problems are usually infodense.

Typically, each example is itself a bunch of smaller examples that all obey the rule. It is the same as how a Bongard Problems relies on many examples to communicate rules; likely just one example wouldn't get the answer across.

On the other hand, in BP1157 for example, each intended rule is communicated by just one example; these rules have to be particularly simple and intuitive, and the individual examples have to be complicated enough to communicate them.

Often, each rule is communicated by showing several examples of things satisfying it. (See keywords left-narrow and right-narrow.) Contrast Bongard Problems, which are more communicative, by showing some examples satisfying the rule and some examples NOT satisfying the rule.

A "rules" Bongard Problem is often collective. Some examples may admit multiple equally plausible rules, and the correct interpretation of each example only becomes clear once the solution is known. The group of examples together improve the solver's confidence about having understood each individual one right.

It is common that there will be one or two examples with multiple reasonable interpretations due to oversight of the author.

All meta Bongard Problems are "rules" Bongard Problems.

Many other Bongard-Problem-like structures seen on the OEBP are also about recognizing a pattern. (See keyword structure.)

"Rules" Bongard Problems are abstract, although the individual rules in them may not be abstract. "Rules" Bongard Problems also usually have the keyword creativeexamples.

Adjacent-numbered pages:
BP1153 BP1154 BP1155 BP1156 BP1157  *  BP1159 BP1160 BP1161 BP1162 BP1163

fuzzy, meta (see left/right), links, keyword, left-self, rules

Aaron David Fairbanks

Left-sorted Problems have the keyword "miniworlds" on the OEBP.

All examples in this Problem are visual Bongard Problems with multiple objects in most panels. This is key as an intuitive set of allowable objects needs to be communicated by any one sorted image.

There is a decent degree of overlap between rules and "miniworlds", but BP1049 is an example of a "miniworlds" problem where the rule is constant across examples, and BP1155 is an example of a "rules" Problem that would not be tagged "miniworlds".

Although this Problem does sort any BP whose examples are images of Bongard Problems left, it is probably best not to consider them to avoid clutter and more unnecessary keywords being attached to them.

Adjacent-numbered pages:
BP1175 BP1176 BP1177 BP1178 BP1179  *  BP1181 BP1182 BP1183 BP1184 BP1185

meta (see left/right), links, keyword

visualbp [smaller | same | bigger]

Leo Crabbe