Adjacent-numbered pages:
BP521 BP522 BP523 BP524 BP525  *  BP527 BP528 BP529 BP530 BP531

meta (see left/right), links, metaconcept

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

Left-sorted BPs have the keyword "left-null" on the OEBP.

Right-sorted BPs have the keyword "right-null" on the OEBP.

See BP796 for the version with pictures of Bongard Problems (miniproblems) instead of links to pages on the OEBP.

See BP1160 for the version about an all-black panel instead of all-white.

Adjacent-numbered pages:
BP562 BP563 BP564 BP565 BP566  *  BP568 BP569 BP570 BP571 BP572

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

visualbp [smaller | same | bigger]

Aaron David Fairbanks

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

Slightly different: sliding the content in a box around without letting it cross the bounding box and without changing the size of the bounding box. (See keyword absoluteposition.)

Expanding the boxes of BP2 ("big vs. small") makes the contents smaller in comparison to the box, but not smaller in an absolute sense. Hence the situation is ambiguous.

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:
BP969 BP970 BP971 BP972 BP973  *  BP975 BP976 BP977 BP978 BP979

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

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

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 a cropped image of a circle, but they fit left because nothing indicates that they are not a cropped image of a circle. A more pedantic solution to this Bongard Problem would be "Could be a cropped image of a circle vs. is definitely not" or "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