Left-sorted Problems often have a specific format or deal with specific geometric shapes.

Almost any Problem that sorts the all-white or all-black panels will be sorted right.

Adjacent-numbered pages:
BP1159 BP1160 BP1161 BP1162 BP1163  *  BP1165 BP1166 BP1167 BP1168 BP1169

notso, meta (see left/right), links, problemkiller

visualbp [smaller | same | bigger]

Leo Crabbe

Bongard Problems sorted left obtain the keyword "viceversa" on the OEBP.

Contrast the keyword notso.

"Viceversa" BPs are often dual.

The solution to a less-than/greater-than quantity comparison Bongard Problem (keyword spectrum) where the two sides divide the spectrum in half can be phrased as "closer to left end of spectrum than right end vs. vice versa." Whether this is a natural way to phrase the solution depends on the kind of quantity being compared.

Here are some examples of spectra for which the "vice versa" phrasing tends to seem natural: left vs. right, up vs. down, black vs. white, higher quantity of [thing type 1] vs. higher quantity of [thing type 2].

Adjacent-numbered pages:
BP1157 BP1158 BP1159 BP1160 BP1161  *  BP1163 BP1164 BP1165 BP1166 BP1167

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

Aaron David Fairbanks

Note that most traditional Bongard Problems don't sort an all black-panel at all.

See BP567 (left-null versus right-null) for the version about all-white panels, which is more often applicable.

Adjacent-numbered pages:
BP1155 BP1156 BP1157 BP1158 BP1159  *  BP1161 BP1162 BP1163 BP1164 BP1165

meta (see left/right), links, side, testexample

Leo Crabbe

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

Right-sorted Bongard Problems have the keyword "right-couldbe".

In a "couldbe" Bongard Problem, some relevant information is left out by the way objects are displayed. Solutions to "left-couldbe" BPs sound like "Could be a ___ vs. definitely not a ___" (and vice versa for "right-couldbe" BPs.)

To put it in mathematical jargon, there is a "projection" function from objects to pictures, such that objects satisfying property X are mapped to the same picture as objects not satisfying property X. Sorted on the "couldbe" side is the image (under projection) of the collection of objects satisfying property X.

Furthermore, usually X is a relatively narrow criterion, so that most objects do not satisfy it (see keywords left-narrow and right-narrow), and all pictures are in the image (under projection) of the collection of objects not satisfying property X.

Consider BP525, "Cropped image of a circle vs. not so." None of the left-hand examples are definitely an image of a circle, but they fit left because nothing indicates that they are not an image of a circle. A more pedantic solution to this Bongard Problem would be "There is a way of cropping a circle that gives this image vs. there isn't."

See also the keyword seemslike, where neither side can be confirmed.

Either "left-couldbe" or "right-couldbe" implies notso.

Although the descriptions of "left-couldbe" and "right-couldbe" sound similar to left-unknowable and right-unknowable, they are not the same. It is the difference between a clear absence of information and perpetual uncertainty about whether there is more information to be found.

"Left-couldbe" is usually left-narrow and "right-couldbe" usually right-narrow.

Adjacent-numbered pages:
BP1154 BP1155 BP1156 BP1157 BP1158  *  BP1160 BP1161 BP1162 BP1163 BP1164

dual, meta (see left/right), links, keyword, side, viceversa

Leo Crabbe

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

This Problem is mostly concerned with categorising BPs whose examples aren't necessarily formatted as traditional Bongard Problems.

Adjacent-numbered pages:
BP1149 BP1150 BP1151 BP1152 BP1153  *  BP1155 BP1156 BP1157 BP1158 BP1159

meta (see left/right), links

visualbp [smaller | same | bigger]

Leo Crabbe

This is a generalisation of Bongard Problems that allows them to have any number of sides. There is a sense in which this problem is about valid vs. invalid ways of partitioning a set of examples into equivalence classes.

https://en.wikipedia.org/wiki/Equivalence_class

Adjacent-numbered pages:
BP1148 BP1149 BP1150 BP1151 BP1152  *  BP1154 BP1155 BP1156 BP1157 BP1158

abstract, teach, meta (see left/right), miniproblems, infodense, structure, rules, miniworlds

zoom in left

Leo Crabbe

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

Bongard Problems sorted right have the keyword "continuous".

All examples are spectrum Bongard Problems.

See BP873 for the version with pictures of Bongard Problems (miniproblems) instead of links to pages on the OEBP.

Adjacent-numbered pages:
BP1147 BP1148 BP1149 BP1150 BP1151  *  BP1153 BP1154 BP1155 BP1156 BP1157

meta (see left/right), links, keyword

Aaron David Fairbanks

This was created as an example for BP1073 (left-it versus right-it).

Adjacent-numbered pages:
BP1145 BP1146 BP1147 BP1148 BP1149  *  BP1151 BP1152 BP1153 BP1154 BP1155

less, meta (see left/right), links, oebp, example, left-self, presentationmatters, right-it, experimental, left-listable, right-listable

Aaron David Fairbanks

Left-sorted Problems usually have a very specific collection of examples, where the only images sorted all show the same type of object.

See unstable vs. stable, which is about examples switching sides upon small changes instead of being rendered unsortable.

See unstableworld vs. stableworld, which is about SOME small change to SOME example making it no longer fit in.

See BP1142 for the version only about additions of detail (no erasures), and with no restriction on them being slight additions.

Adjacent-numbered pages:
BP1139 BP1140 BP1141 BP1142 BP1143  *  BP1145 BP1146 BP1147 BP1148 BP1149

meta (see left/right), links, problemkiller

Aaron David Fairbanks