Editing Commonsense reasoning (section)

== Successes in automated commonsense reasoning ==
Significant progress in the field of the automated commonsense reasoning is made in the areas of the taxonomic reasoning, actions and change reasoning, reasoning about time. Each of these spheres has a well-acknowledged theory for wide range of commonsense inferences.<ref>{{Cite web|url = http://www.encyclopedia.com/doc/1O11-commonsensereasoning.html|title = Taxonomy}}</ref>

=== Taxonomic reasoning ===
Taxonomy is the collection of individuals and categories and their relations. Three basic relations are:
* An individual is an instance of a category. For example, the individual ''Tweety'' is an instance of the category ''robin''.
* One category is a subset of another. For instance ''robin'' is a subset of ''bird''.
* Two categories are disjoint. For instance ''robin'' is disjoint from ''penguin''.
Transitivity is one type of inference in taxonomy. Since ''Tweety'' is an instance of ''robin'' and ''robin'' is a subset of ''bird'', it follows that ''Tweety'' is an instance of ''bird''. Inheritance is another type of inference. Since ''Tweety'' is an instance of ''robin'', which is a subset of ''bird'' and ''bird'' is marked with property ''canfly'', it follows that ''Tweety'' and ''robin'' have property ''canfly''.

When an individual taxonomizes more abstract categories, outlining and delimiting specific categories becomes more problematic. Simple taxonomic structures are frequently used in AI programs. For instance, [[WordNet]] is a resource including a taxonomy, whose elements are meanings of English words. [[Web mining]] systems used to collect commonsense knowledge from Web documents focus on taxonomic relations and specifically in gathering taxonomic relations.<ref name="Davis Marcus"/>

=== Action and change ===
The theory of action, events and change is another range of the commonsense reasoning.<ref>{{Cite web|url = http://www-formal.stanford.edu/jmc/someneed/node3.html|title = Action and change in Commonsense reasoning}}</ref> There are established reasoning methods for domains that satisfy the constraints listed below:
* Events are atomic, meaning one event occurs at a time and the reasoner needs to consider the state and condition of the world at the start and at the finale of the specific event, but not during the states, while there is still an evidence of on-going changes (progress).
* Every single change is a result of some event
* Events are deterministic, meaning the world's state at the end of the event is defined by the world's state at the beginning and the specification of the event.
* There is a single actor and all events are their actions.
* The relevant state of the world at the beginning is either known or can be calculated.

=== Temporal reasoning ===
{{further|Spatial–temporal reasoning}}
Temporal reasoning is the ability to make presumptions about humans' knowledge of times, durations and time intervals. For example, if an individual knows that Mozart was born after Haydn and died earlier than him, they can use their temporal reasoning knowledge to deduce that Mozart had died younger than Haydn. The inferences involved reduce themselves to solving systems of linear inequalities.<ref>{{Cite web|url = http://www-formal.stanford.edu/leora/commonsense/|title = Temporal reasoning}}</ref>

To integrate that kind of reasoning with concrete purposes, such as [[natural-language understanding|natural language interpretation]], is more challenging, because natural language expressions have context dependent interpretation.<ref>Liu, Hugo, and Push Singh. "[http://larifari.org/_/writing/KES2004-CommonSenseNL.pdf Commonsense reasoning in and over natural language] {{Webarchive|url=https://web.archive.org/web/20170809032506/http://larifari.org/_/writing/KES2004-CommonSenseNL.pdf |date=2017-08-09 }}." International Conference on Knowledge-Based and Intelligent Information and Engineering Systems. Springer, Berlin, Heidelberg, 2004.</ref> Simple tasks such as assigning timestamps to procedures cannot be done with total accuracy.

=== Qualitative reasoning ===
{{main|Qualitative reasoning}}

Qualitative reasoning<ref>{{Cite web|url = https://techcrunch.com/2014/08/09/guide-to-common-sense-reasoning-whos-doing-it-and-why-it-matters/|title = Qualitative reasoning| date=9 August 2014 }}</ref> is the form of commonsense reasoning analyzed with certain success. It is concerned with the direction of change in interrelated quantities. For instance, if the price of a stock goes up, the amount of stocks that are going to be sold will go down. If some ecosystem contains wolves and lambs and the number of wolves decreases, the death rate of the lambs will go down as well. This theory was firstly formulated by [[Johan de Kleer]], who analyzed an object moving on a roller coaster.

The theory of qualitative reasoning is applied in many spheres such as physics, biology, engineering, ecology, etc. It serves as the basis for many practical programs, analogical mapping, text understanding.