Acquiring Literacy in English:
Crosslinguistic, Intralinguistic, and Developmental Factors

Extract the Base Test

Authors and Date

Diane August, Dorry Kenyon, Valerie Malabonga, Mohammed Louguit and Silvia Caglarcan, Center for Applied Linguistics; Maria Carlo, University of Miami. 2001.


The English version of the Extract the Base Test assesses Spanish-speaking children’s knowledge of the rules that govern the way in which words change from one part of speech to another in English. The Spanish version assesses their knowledge of analogous rules in Spanish. The tests were developed for the research study Transfer of Reading Skills in Bilingual Children, subproject 2 of Acquiring Literacy in English: Crosslinguistic, Intralinguistic, and Developmental Factors.

Age or Grade of Examinees

The pilot version was tested on third, fourth, and fifth graders. The revised version was used with fourth and fifth graders.


The tests require the student to extract the base from a derived word (for example, farm from farmer [English]; mejor from mejorar [Spanish]). Students are presented with a series of sentences, and the tester supplies the derived form orally and visually. For example, on the English test, students see the word farmer and the sentence: “My uncle works on a _____.” The researcher says the word farmer, then reads the sentence and asks the students to write the appropriate word (farm) in the blank.

The words in the English version represent four kinds of morphological transformations:  phonological change, orthographic change, both changes, and no change. In phonological change, the pronunciation of the word changes but the spelling does not. In orthographic change, the spelling of the word changes but the pronunciation does not. In both changes, the pronunciation and spelling of the word change. In no change, neither the pronunciation nor the spelling of the word changes.


Transformation Type

Derived Form


Phonological change


The _________ was happy with the show.

Orthographic change


My pet dog makes me very ___________.

Both changes


I ____________ you did your homework.

No change


Handle those glasses with ____________.

In the Spanish version, each word represents either both changes (phonological and orthographic) or no change.


Transformation Type

Derived Form


Both changes


Mi tío es muy _______________ .

No change


Ten ____________ con esos anteojos.



The test is group administered and usually takes about 30 minutes.

Scoring and Interpretation

On the English Extract the Base Test, the children’s responses were coded as follows:





Correct: Correct base, correct spelling


Partial Credit: Correct base, incorrect spelling (e.g., spelling according to pronunciation of word or regional or dialectical differences and Spanish influence) and/or other inflectional morphology errors (e.g., incorrect use of gender, tense & plural)


Incorrect: Incorrect base, regardless of spelling and/or other morphological problems


Reliability and Validity

For the English version, a reliability of .98 was obtained through a Rasch analysis. Validation data are pending.


The Extract the Base Test was adapted from tasks described by Carlisle (1989) and Anglin (1993).

Anglin, J. M. (1993). Vocabulary development: A morphological analysis. Monographs of the Society for Research in Child Development, 58(10), 1-166.

Carlisle, J. F. (1988). Knowledge of derivational morphology and spelling ability in fourth, sixth, and eighth graders. Applied Psycholinguistics, 9(3), 247-266.


The Extract the Base Test in English is available from the Center for Applied Linguistics. To request a copy, complete and submit the Application Form for Use of ALE Researcher-developed Assessment Instruments, available in Microsoft Word and Adobe PDF format.

The Extract the Base Test in Spanish is not available for use by researchers outside the Center for Applied Linguistics.


Researchers using the Extract the Base Test—English should cite it as follows:

August, D., Kenyon, D., Malabonga, V., Louguit, M., Caglarcan, S., & Carlo, M. (2001). Extract the Base Test—English. Washington, DC: Center for Applied Linguistics.

Return to the list of researcher-developed assessments.