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

Right-sorted Bongard Problems have the keyword "finished" on the OEBP.

Users are not able to add or remove examples from Problems tagged "finished." (This is unusual; most Bongard Problems on the OEBP can be expanded indefinitely by users.)

A "finished" Bongard Problem will always admit the alternate, convoluted solution "is [left example 1] OR is [left example 2] OR . . . OR is [last left example] vs. is [right example 1] OR is [right example 2] OR . . . OR is [last right example]".

Bongard's original Problems are tagged "finished."

Adjacent-numbered pages:
BP499 BP500 BP501 BP502 BP503  *  BP505 BP506 BP507 BP508 BP509

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

bppage [smaller | same | bigger]

Aaron David Fairbanks

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

Meta Bongard Problems are Bongard Problems that sort Bongard Problems. Sometimes abbreviated MBPs.

The first meta Bongard Problem was BP200.

Some meta BP pages sort images of Bongard Problems (keyword miniproblems), while other meta BP pages sort other BP pages (keyword links).

BPs that sort meta-BPs are labelled metameta.

Adjacent-numbered pages:
BP532 BP533 BP534 BP535 BP536  *  BP538 BP539 BP540 BP541 BP542

meta (see left/right), links, keyword, world, left-self, sideless, metameta, left-full, feedback

bp [smaller | same | bigger]
zoom in left (linksbp)

Aaron David Fairbanks

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

Right examples have the keyword "traditional" on the OEBP.

Experimental BPs push the boundaries of what makes Bongard Problems Bongard Problems.

Traditional BPs show some simple property of black and white pictures. The OEBP is a place with many wild and absurd Bongard Problems, so it is useful to have an easy way to just find the regular old Bongard Problems.

Adjacent-numbered pages:
BP545 BP546 BP547 BP548 BP549  *  BP551 BP552 BP553 BP554 BP555

subjective, meta (see left/right), links, keyword, left-it

bp [smaller | same | bigger]

Aaron David Fairbanks

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

If mirroring any example along the any axis can change its sorting the BP is "handed."

Note that BPs about comparing orientation between multiple things in one example fit on the right side.

See BP871 for the version with pictures of Bongard Problems (miniproblems) instead of links to pages on the OEBP.

The keyword leftright is specifically about flipping over the vertical axis, while the keyword updown is specifically about flipping over the horizontal axis.

Bongard Problems tagged rotate are usually "handed", since any rotation can be created by two reflections. Not necessarily, however, since the reflected step in between might not be sorted on either side by the Bongard Problem.

Adjacent-numbered pages:
BP547 BP548 BP549 BP550 BP551  *  BP553 BP554 BP555 BP556 BP557

meta (see left/right), links, keyword, invariance, wellfounded

visualbp [smaller | same | bigger]
zoom in left (handed_visualbp)

Aaron David Fairbanks

Right-sorted BPs have the keyword "gap" on the OEBP.

A Bongard Problem with a gap showcases two completely separate classes of objects.

For example, the Bongard Problem "white vs. black" (BP962) has a gap; there is no obvious choice of shared context between the two sides. One could imagine there is a spectrum of grays between them, or that there is a space of partially filled black-and-white images between them, or any number of other ambient contexts.

Bongard Problems about comparing quantities on a spectrum should not usually be considered "gap" BPs. (Discrete spectra perhaps.) A spectrum establishes a shared context, with examples on both sides of the BP landing somewhere on it. (However, if it is reasonable to imagine getting the solution without noticing a spectrum in between, it could be a gap, since the ambient context is unclear.)

Bongard Problems with gaps may seem particularly arbitrary when the two classes of objects are particularly unrelated.

If a Bongard Problem has a "gap" it is likely precise: it will likely be clear on which side any potential example fits.

"Gap" implies stable. (This technically includes cases in which ALL small changes make certain examples no longer fit in with the Bongard Problem, as is sometimes the case in "gap" BPs. See also BP1144.)

See also preciseworld. "Gap" Bongard Problems would be tagged "preciseworld" when the two classes of objects are each clear; it is then apparent that there is no larger shared context and that no other types of objects besides the two types would be sorted by the Bongard Problem.

See BP1140, which is about any (perhaps large) additions instead of repeated small changes.

Adjacent-numbered pages:
BP959 BP960 BP961 BP962 BP963  *  BP965 BP966 BP967 BP968 BP969

unwordable, meta (see left/right), links, keyword, sideless, invariance

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

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

Most Bongard Problems relating to the OEBP are meta.

Adjacent-numbered pages:
BP1108 BP1109 BP1110 BP1111 BP1112  *  BP1114 BP1115 BP1116 BP1117 BP1118

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

Leo Crabbe

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

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

The repositioned content has to stay within the box. If an example in a Bongard Problem features content touching a border (keyword bordercontent), then that prevents the contents from being shifted in that direction.

If a Bongard Problem has the keyword "absoluteposition", then it likely has the keyword boundingbox.

If a Bongard Problem has the keyword boundingbox and does not have the keyword bordercontent, then it likely has the keyword "absoluteposition".

Adjacent-numbered pages:
BP1190 BP1191 BP1192 BP1193 BP1194  *  BP1196 BP1197 BP1198 BP1199 BP1200

meta (see left/right), links, keyword, invariance

Aaron David Fairbanks

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

All of Bongard's original Problems have whitespace around the border of all examples.

Adjacent-numbered pages:
BP1191 BP1192 BP1193 BP1194 BP1195  *  BP1197 BP1198 BP1199 BP1200 BP1201

meta (see left/right), links, keyword

Aaron David Fairbanks