Developmental Measures

Several developmental measures are defined as Reader methods:

mlu([participant])

Return the mean lengths of utterance (MLU).

mlum([participant])

Return the mean lengths of utterance by morphemes.

mluw([participant])

Return the mean lengths of utterance by words.

ttr([keep_case, participant])

Return the type-token ratios (TTR).

ipsyn([participant])

Return the indexes of productive syntax (IPSyn).

For the mean lengths of utterance (MLU) in Eve’s data from Brown:

>>> import pylangacq
>>> url = "https://childes.talkbank.org/data/Eng-NA/Brown.zip"
>>> eve = pylangacq.read_chat(url, "Eve")
>>> eve.mlu()
[2.309041835357625,
 2.488372093023256,
 2.8063241106719365,
 2.6153846153846154,
 2.8866855524079322,
 3.208955223880597,
 3.179732313575526,
 3.4171011470281543,
 3.840077071290944,
 3.822669104204753,
 3.883668903803132,
 4.177847113884555,
 4.2631578947368425,
 3.976890756302521,
 4.457182320441989,
 4.422776911076443,
 4.498338870431894,
 4.292035398230088,
 4.3813169984686064,
 3.320964749536178]