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

Right-sorted Bongard Problems have the keyword "less." They are not necessarily "bad," but we do not want more like them.

Adjacent-numbered pages:
BP498 BP499 BP500 BP501 BP502  *  BP504 BP505 BP506 BP507 BP508

subjective, meta (see left/right), links, keyword, oebp, right-finite, left-it, feedback, time

bp [smaller | same | bigger]

Aaron David Fairbanks

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

This sorts Bongard Problems based on how BP513 (left-narrow) would sort them if they were flipped; see that page for a description.

Adjacent-numbered pages:
BP509 BP510 BP511 BP512 BP513  *  BP515 BP516 BP517 BP518 BP519

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

bp [smaller | same | bigger]

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

Adjacent-numbered pages:
BP673 BP674 BP675 BP676 BP677  *  BP679 BP680 BP681 BP682 BP683

meta (see left/right), links, metaconcept, primitive

bp [smaller | same | bigger]

Harry E. Foundalis

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

Some Bongard Problems are "collective" in a more extreme way than others. Perhaps there are absolutely no individual examples that anyone would confidently sort on either side, and the solver can only be expected to get a vague gist by seeing them all together. Or perhaps in practice most people agree about where most examples should fit, even though a stretch of an argument could conceivably be made for each one fitting on the other side.

In some collective Bongard Problems, each example admits a number of possible interpretations, and the correct choice of interpretation is only clear once the solution is known. The group of examples together improve the solver's confidence about having understood each individual one right. This is common in rules Bongard Problems), where each example communicates its own rule.

Collective Bongard Problems are borderline invalid Bongard Problems (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. It is a less strict kind of Bongard Problem.

Collective implies fuzzy.

Collective Bongard Problems are often abstract".

Subjective Bongard Problems are often collective.

In some Bongard Problems, each example has a corresponding slightly different twin example on the other side (keyword contributepairs), and it is necessary to see both examples together in order to be able to sort either of them. This is related to "collective" but not quite the same. It becomes unambiguous where an example fits once its twin is seen.

Adjacent-numbered pages:
BP832 BP833 BP834 BP835 BP836  *  BP838 BP839 BP840 BP841 BP842

meta (see left/right), links, keyword

bp [smaller | same | bigger]

Aaron David Fairbanks

Alternatively, BP pages on the OEBP with number less than or equal to 394 vs. other BP pages.

https://www.foundalis.com/res/bps/bpidx.htm

Adjacent-numbered pages:
BP1189 BP1190 BP1191 BP1192 BP1193  *  BP1195 BP1196 BP1197 BP1198 BP1199

Foundalis's collection includes all Bongard Problems by Bongard.

meta (see left/right), links, right-self, time

Aaron David Fairbanks