BPs sorted left are tagged with the keyword "abstract" on the OEBP. The solution is not an easily-checked or concretely-defined geometrical or numerical property in pictures.

Adjacent-numbered pages:
BP507 BP508 BP509 BP510 BP511  *  BP513 BP514 BP515 BP516 BP517

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

bp [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

Adjacent-numbered pages:
BP633 BP634 BP635 BP636 BP637  *  BP639 BP640 BP641 BP642 BP643

meta (see left/right), links, metaconcept

bp [smaller | same | bigger]

Harry E. Foundalis

Adjacent-numbered pages:
BP682 BP683 BP684 BP685 BP686  *  BP688 BP689 BP690 BP691 BP692

meta (see left/right), links, metaconcept, primitive, left-it, feedback

bp [smaller | same | bigger]

Harry E. Foundalis

Adjacent-numbered pages:
BP686 BP687 BP688 BP689 BP690  *  BP692 BP693 BP694 BP695 BP696

meta (see left/right), links, metaconcept, primitive, left-it, feedback

bp [smaller | same | bigger]

Harry E. Foundalis

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

Examples of "structures": Bongard Problem, Bongard Problem with extra unsorted panel ("Bongard's Dozen"), 4-panel analogy grid, sequence of objects with a quantity changing by a constant amount.

If the solver hasn't become familiar with the featured structure, the Bongard Problem's solution may seem convoluted or inelegant. (See keyword assumesfamiliarity.) Once the solver gets used to seeing a particular structure it becomes easier to read that structure and solve Bongard Problems featuring it.

A Bongard Problem can non-verbally teach someone how a particular structure works, showing valid examples of that structure versus non-examples. E.g., BP968 for the structure of Bongard Problems and BP981 for the structure of analogy grids.

Adjacent-numbered pages:
BP784 BP785 BP786 BP787 BP788  *  BP790 BP791 BP792 BP793 BP794

meta (see left/right), links, keyword

bp [smaller | same | bigger]

Aaron David Fairbanks

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

Be encouraged to contribute new interesting examples to Bongard Problems with this keyword.

There is much overlap with the keyword hardsort.

This is what it usually means to say examples fit on (e.g.) the left of a Bongard Problem in various creative ways: there is no (obvious) general method to determine a left-fitting example fits left.

There is a related idea in computability theory: a "non recursively enumerable" property is one that cannot in general be checked by a computer algorithm.

But keep in mind the tag "creativeexamples" is supposed to mean something less formal. For example, it requires no ingenuity for a human being to check when a simple shape is convex or concave (so BP4 is not labelled "creativeexamples"). However, it is not as if we use an algorithm to do this, like a computer. (It is not even clear what an "algorithm" would mean in this context, since it is ambiguous both what class of shapes the Bongard Problem sorts and how that would be encoded into a computer program's input. There are usually many options and ambiguities like this whenever one tries to formalize the content of a Bongard Problem.)

Adjacent-numbered pages:
BP861 BP862 BP863 BP864 BP865  *  BP867 BP868 BP869 BP870 BP871

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

bp [smaller | same | bigger]

Aaron David Fairbanks

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

Many things might be called "creating a picture". For example, drawing a path in a maze. However, use this keyword to indicate a Bongard Problem requires the solver to create something totally new "on a separate piece of paper" (whether mentally or physically), beyond just annotating the existing picture.

A "visualimagination" BP will likely be hardsort.

"Visualimagination" BPs are abstract.

"Visualimagination" BPs are are often about deciding whether some potential thing exists. (See BP634 for Bongard Problems featuring the concept ofexistence.) One can demonstrate it exists by constructing it.

Adjacent-numbered pages:
BP955 BP956 BP957 BP958 BP959  *  BP961 BP962 BP963 BP964 BP965

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

Aaron David Fairbanks

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

Sometimes all the examples in a Bongard Problem need to be interpreted a certain way for the Bongard Problem to make sense. Only once the representation is understood, the idea seems simple.

For example, all meta Bongard Problems (Bongard Problems sorting other Bongard Problems) assume the solver interprets the examples as Bongard Problems.

TO DO: Maybe it is best to stop putting the label "assumesfamiliarity" on all meta-Bongard Problems. There are so many of them. It may be better to only use the "assumesfamiliarity" keyword on meta-BPs for a further assumption than just that all examples are interpreted as Bongard Problems. - Aaron David Fairbanks, Feb 11 2021

Many Bongard Problems in which all examples take the same format (keyword structure) assume the solver already knows how to read that format.

Some Bongard Problems assume the solver will be able to understand symbolism that is consistent between examples (keyword consistentsymbols).

Bongard Problems tagged math often assume the solver is familiar with a certain representation of a math idea.

Adjacent-numbered pages:
BP1106 BP1107 BP1108 BP1109 BP1110  *  BP1112 BP1113 BP1114 BP1115 BP1116

BP1032: The solution should really read "Assuming all images are Bongard Problems sorting each natural number left or right ..." This Bongard Problem makes sense to someone who has been solving a series of similar BPs, but otherwise there is no reason to automatically read a collection of numbers as standing for a larger collection of numbers.

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

bp [smaller | same | bigger]

Aaron David Fairbanks