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

Although everything is arguably related to math, these BP solutions include content that people don't inherently understand without learning at least some mathematics.

Left examples do not technically have "culturally-dependent" content (keyword culture), but knowledge and previous learning plays a role in how easy they are to solve.

Adjacent-numbered pages:
BP566 BP567 BP568 BP569 BP570  *  BP572 BP573 BP574 BP575 BP576

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

bp [smaller | same | bigger]

Aaron David Fairbanks

Adjacent-numbered pages:
BP650 BP651 BP652 BP653 BP654  *  BP656 BP657 BP658 BP659 BP660

meta (see left/right), links, metaconcept

bp [smaller | same | bigger]

Harry E. Foundalis

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

Contrast "hardsort" to infodense, where examples have a high amount of information, but perhaps after parsing all the information in the examples it is easy to sort them.

BPs labelled "hardsort" are likely to be labelled hard, but perhaps not--e.g. in BP323 the answer is easy to guess, but laborious to verify.

Adjacent-numbered pages:
BP859 BP860 BP861 BP862 BP863  *  BP865 BP866 BP867 BP868 BP869

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

bp [smaller | same | bigger]

Aaron David Fairbanks

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

If applying a scaling along one particular axis to the whole of any example can change its sorting the BP fits on the left side here. (For BPs with bounding boxes this means scaling and cropping, but without cutting out any detail.)

Adjacent-numbered pages:
BP1107 BP1108 BP1109 BP1110 BP1111  *  BP1113 BP1114 BP1115 BP1116 BP1117

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

[smaller | same | bigger]

Leo Crabbe