[Paper Review - Psycholinguistics] Reexamining the Vocabulary Spurt (Ganger & Brent, 2004)

Reexamining the Vocabulary Spurt

Ganger & Brent (2004)

• Research question: the existence of the vocabulary spurt? 
• Data: Longitudinal data from 38 children 
• Method: the rate of word learning with 2 functions (i.e., one with an inflection point (logistic) and the other without an inflection point (quadratic) 

 

2;0 around 300 words / 18;0 around 60,000 words 

After 50-100 words learning, vocabulary spurt? (Dapretto & Bjork, 2000) 

Theories of the vocabulary spurt

• The vocabulary spurt coincides with a major cognitive change: the naming insight (the realization that words refer to things or that all things have names) -> this insight marks a shift in the use of words from vocalizations associated with specific routines to true adult words that may be used to refer -> after having this insight, children begin to acquire words at a rapid pace. 
• The spurt marks a change in children's object concepts. Infants begin to use words when they enter Piaget's Sensorimotor Substage 6 (learn symbols?) and then show a vocabulary spurt as their object concepts become more detailed and differentiated. 
• The child's ability to sort objects into groups based on category membership improves around the time of the vocabulary spurt. 
• The vocabulary spurt occurs when word segmentation has been solved, implying that the ability to pick the words out from running speech opens the floodgates to producing many new words 
• The segmental representation of words changes as the vocabulary spurt occurs, leading to the ability to represent words in more accurate detail as more and more words are learned 
• Advances in pragmatics are correlated with the vocabulary spurt, suggesting that gains in social cognition permit the acquisition of words at a higher rate. 
• The spurt in productive vocabulary is driven by the development of word retrieval abilities. 

The vocabulary spurt as a developmental milestone 

 

Identifying the spurt

• 3 methods 
• To estimate a child's overall vocabulary size and age 
• Produce a graph of vocabulary size over time 
• Threshold approach: a threshold of words per unit of time must be crossed 

Defining the spurt clearly 

• The key property of the vocabulary spurt is that it consists of discrete developmental stages rather than continuous incremental improvement. 
• A true developmental spurt must be a transition between a slow learning stage and a faster learning stage. 
• Faster learning rate should be sustained for some period of time. 

 A new method

• One that tests whether the changes in a child's rate of word learning represent distinct stages with a transition in between. 
• y  = a / (1 + e-b(x – c)) 

a -> the rate of learning after the transition  (asymptote) 

b -> the length of time over which the transition occurs (the slope of the function at the transition point) 

c -> the point at which the transition occurs (inflection point)