The data on place of birth were derived from answers to Question 7. Respondents were asked to select one of two categories:
(1) in the United States, or
(2) outside the United States. In the American Community Survey, respondents selecting category
(1) were then asked to report the name of the state while respondents selecting category
(2) were then asked to report the name of the foreign country, or Puerto Rico, Guam, etc. In the Puerto Rico Community Survey, respondents selecting category
(1) were also asked to report the name of the state, while respondents selecting category
(2) were then asked to print Puerto Rico or the name of the foreign country, or U.S. Virgin Islands, Guam, etc. People not reporting a place of birth were assigned the state or country of birth of another family member, or were allocated the response of another individual with similar characteristics. People born outside the United States were asked to report their place of birth according to current international boundaries. Since numerous changes in boundaries of foreign countries have occurred in the last century, some people may have reported their place of birth in terms of boundaries that existed at the time of their birth or emigration, or in accordance with their own national preference.

Data on language spoken at home were derived from answers to the 2008 American Community Survey Questions 13a and 13b. These questions were asked only of persons 5 years of age and older. Instructions mailed with the American Community Survey questionnaire instructed respondents to mark "Yes" on Question 13a if they sometimes or always spoke a language other than English at home, and "No" if a language was spoken only at school - or if speaking was limited to a few expressions or slang. For Question 13b, respondents printed the name of the non-English language they spoke at home. If the person spoke more than one non-English language, they reported the language spoken most often. If the language spoken most frequently could not be determined, the respondent reported the language learned first.

Questions 13a and 13b referred to languages spoken at home in an effort to measure the current use of languages other than English. This category excluded respondents who spoke a language other than English exclusively outside of the home.

Most respondents who reported speaking a language other than English also spoke English. The questions did not permit a determination of the primary language of persons who spoke both English and another language.

An automated computer system coded write-in responses to Question 13b into more than 380 detailed language categories. This automated procedure compared write-in responses with a master computer code list - which contained approximately 55,000 previously coded language names and variants - and then assigned a detailed language category to each write-in response. The computerized matching assured that identical alphabetic entries received the same code. Clerical coding categorized any write-in responses that did not match the computer dictionary. When multiple languages other than English were specified, only the first was coded.
The write-in responses represented the names people used for languages they spoke. They may not have matched the names or categories used by professional linguists. The categories used were sometimes geographic and sometimes linguistic. The following table provides an illustration of the content of the classification schemes used to present language data.
Four and Thirty-Nine Group Classifications of Languages Spoken at Home with Illustrative Examples

Four-Group Classification	Thirty-nine Group Classification	Examples
Spanish	Spanish or Spanish Creole	Spanish, Ladino, Pachuco
Other Indo-European languages	French	French, Cajun, Patois
	French Creole	Haitian Creole
	Italian	Italian
	Portuguese or Portuguese Creole	Portuguese, Papia Mentae
	German	German, Luxembourgian
	Yiddish	Yiddish
	Other West Germanic languages	Dutch, Pennsylvania Dutch, Afrikaans
	Scandinavian languages	Danish, Norwegian, Swedish
	Greek	Greek
	Russian	Russian
	Polish	Polish
	Serbo-Croatian	Serbo-Croatian, Croatian, Serbian
	Other Slavic languages	Czech, Slovak, Ukrainian
	Armenian	Armenian
	Persian	Persian
	Gujarathi	Gujarathi
	Hindi	Hindi
	Urdu	Urdu
	Other Indic languages	Bengali, Marathi, Punjabi, Romany
	Other Indo-European languages	Albanian, Gaelic, Lithuanian,Rumanian
Asian and Pacific Island languages	Chinese	Cantonese, Formosan, Mandarin
	Japanese	Japanese
	Korean	Korean
	Mon-Khmer, Cambodian	Mon-Khmer, Cambodian
	Hmong	Hmong
	Thai	Thai
	Laotian	Laotian
	Vietnamese	Vietnamese
	Other Asian languages	Dravidian languages (Malayalam, Telugu, Tamil),Turkish
	Tagalog	Tagalog
	Other Pacific Island languages	Chamorro, Hawaiian, Ilocano, Indonesian, Samoan
All other languages	Navajo	Navajo
	Other Native North American languages	Apache, Cherokee, Dakota, Pima, Yupik
	Hungarian	Hungarian
	Arabic	Arabic
	Hebrew	Hebrew
	African languages	Amharic, Ibo, Twi, Yoruba, Bantu, Swahili, Somali
	Other and unspecified languages	Syriac, Finnish, Other languages of the Americas, not reported

Respondents who reported speaking a language other than English were asked to indicate their English-speaking ability based on one of the following categories: "Very well," "Well," "Not well," or "Not at all." Ideally, the data on ability to speak English represented a person's perception of their own English-speaking ability. However, because one household member usually completes American Community Survey questionnaires, the responses may have represented the perception of another household member. Respondents were not instructed on how to interpret the response categories in Question 13c.

The U.S. Census Bureau treats the Commonwealth of Puerto Rico as the statistical equivalent of a state for data presentation purposes. Each state and statistically equivalent entity is assigned a two-digit Federal Information Processing Standards (FIPS) code in alphabetical order by state name, followed in alphabetical order by Puerto Rico and the Island Areas. Each state and statistically equivalent entity also is assigned the two-letter FIPS/U.S. Postal Service code.