Editing Fast mapping (section)

=== Alternate theories ===
An alternate theory of deriving the meaning of newly learned words by young children during language acquisition stems from John Locke's "associative proposal theory". Compared to the "intentional proposal theory", associative proposal theory refers to the deduction of meaning by comparing the novel object to environmental stimuli.  A study conducted by Yu & Ballard (2007), introduced cross-situational learning,<ref>{{cite journal|author=Chen, Yu|url=http://www.indiana.edu/~dll/papers/yu_psychscience07.pdf|title=Rapid Word Learning Under Uncertainty via Cross-Situational Statistics|journal=Psychological Science|volume=18|issue=5|year=2006|access-date=18 September 2013|doi=10.1111/j.1467-9280.2007.01915.x|pmid=17576281|pages=414–420|citeseerx=10.1.1.385.7473|s2cid=729528}}</ref> a method based on Locke's theory. Cross-situational learning theory is a mechanism in which the child learns meaning of words over multiple exposures in varying contexts in an attempt to eliminate uncertainty of the word's true meaning on an exposure-by-exposure basis.<ref>{{cite book|author=Frank, Michael|url=http://langcog.stanford.edu/papers/F-chapterunderreview.pdf|title=Learning words through probabilistic inferences about speakers' communicative intentions|access-date=18 September 2013}}</ref>

On the other hand, more recent studies<ref name="Medina">{{cite journal|author=Medina, T. N.|author2=Snedeker, J.|author3=Trueswell, J. C.|author4=Gleitman, L. R.|year=2010|title=How words can and cannot be learned by observation|doi=10.1073/pnas.1105040108|pmid=21576483|pmc=3107260|pages=9014–9019|volume=108|issue=22|journal=PNAS|bibcode=2011PNAS..108.9014M|doi-access=free}}</ref> suggest that some amount of fast mapping does take place, questioning the validity of previous laboratory studies that aim to show that probabilistic learning does occur.  A critique to the theory of fast mapping is how can children connect the meaning of the novel word with the novel word after just one exposure? For example, when showing a child a blue ball and saying the word "blue" how does the child know that the word blue explains the color of the ball, not the size, or shape? If children learn words by fast mapping, then they must use inductive reasoning to understand the meaning associated with the novel word. A popular theory to explain this inductive reasoning is that children apply [[Word learning biases|word-learning constraints]] to the situation where a novel word is introduced. There are speculations as to why this is; Markman and Wachtel (1988) conducted a study that helps explain the possible underlying principles of fast mapping. They claim children adhere to the theories of [[Word learning biases#cite note-Hansen-3|whole-object bias]], the assumption that a novel label refers to the entire object rather than its parts, color, substance or other properties, and mutual exclusivity bias, the assumption that only one label applies to each object.<ref>{{cite journal | last1 = Hansen | first1 = M.B. | last2 = Markman | first2 = E.M. | year = 2009 | title = Children's use of mutual exclusivity to learn labels for parts of objects | journal = Developmental Psychology | volume = 45 | issue = 2| pages = 592–596 | doi=10.1037/a0014838| pmid = 19271842 }}</ref> In their experiment, children were presented with an object that they either were familiar with or was presented with a whole object term. Markman and Watchel concluded that the mere juxtaposition between familiar and novel terms may assist in part term acquisition. In other words, children will put constraints on themselves and assume the novel term refers to the whole object in view rather than to its parts.<ref name=Almgren>{{cite book|author=Braisby, Nick |author2=Dockrell, Julie E. |author3=Best, Rachel M.|year=2001|chapter=Children's acquisition of science terms: does fast mapping work?|editor=Almgren, Margareta |editor2=Barreña, Adoni |editor3=Ezeizabarrena, María-José |editor4=Idiazabal, Itziar |editor5=MacWhinney, Brian |title=Research on child language acquisition: proceedings of the 8th Conference of the International Association for the Study of Child Language|location=Somerville, MA, USA|publisher=Cascadilla Press|pages=1066–1087|chapter-url=http://oro.open.ac.uk/3641/1/IASCL_Paper_II.pdf| archive-url=https://web.archive.org/web/20121207154225/http://oro.open.ac.uk/3641/1/IASCL_Paper_II.pdf | archive-date=2012-12-07 | url-status=dead |isbn=978-1-57473-119-4}}</ref> There have been six lexical constraints proposed (reference, extendibility, object scope, categorical scope, novel name, conventionality) that guide a child's learning of a novel word.<ref name=Almgren/> When learning a new word children apply these constraints. However, this purposed method of constraints is not flawless. If children use these constraints there are many words that children will never learn such as actions, attributes, and parts. Studies have found that both toddlers and adults were more likely to categorize an object by its shape than its size or color.<ref name=Trueswell/>