Question

A language psychologist is interested in whether or not bilingualism causes people to have enhanced word vocabulary on their first language. (That is the language that they learned in their family setting from infancy.) She collects as set of 400 obscure words [words that are not part of their everyday lives] her participants’ first language. She tests 45 bilingual people and counts the number of words from this list they define correctly.

Data	Bilinguals	Monolinguals
Observed	30	15

From a previous study she knows the average number of words from this list monolingual can correctly identify. She divides the number of bilingual people in her sample into those who exceed this number and those who do not (frequency of exceeding mono-linguals). The data from her study are presented in the table above. Compute the chi-squared statistic for this study using an assumption of equal expected values for each condition. Report your obtained χ² in proper statistical reporting format. And use an alpha level of 0.05. Is there a significant difference in bilingual vocabulary? Is it in the direction that the language psychologist hypothesized? Can the language psychologist conclude that bilingual people have better vocabularies in their first language? Be sure to show your calculations for full credit.

Answer 1

chi square test