Alternate norm referencing - calculator
To begin, download the CHESL Language Development Calculator sheet (.XLS) Be sure to download as .xls. Only enter numbers in the red boxes
RESOURCES REQUIRED TO USE THE CALCULATOR SHEET
Each calculator uses a combination of the following scores plus the child's length of exposure to English. Not all test and sub-test scores are needed for every calculator. The minimum is: ALDeQ, TEGI Screener and CTOPP non-word repetition (calculator 6).
Child's length of exposure to English in months; see Calculating Exposure to English for the simplified method of obtaining this information.
ALDeQ score - this is a proportion from 0-1.0; see Questionnaires: ALDeQ
ENNI standard scores; see Edmonton Narrative Norms Instrument below.
TEGI screener score- this is a proportion from 0-1.0; see Test of Early Grammatical Impairment below.
CTOPP non-word repetition sub-test standard score; see Comprehensive Test of Phonological Processing below.
PPVT standard score; see Peabody Picture Vocabulary Test below.
The following information will help you use the calculator sheet correctly:
Calculators give a probability from 0-1.0. Probabilities of 0.5-1.0 indicate that a child's test performance patterns are more consistent with the children in this research who have language impairment.
The sensitivity and specificity of each combination of test scores is given on the calculator sheet:
Sensitivity expresses that calculator's ability to correctly classify children as language impaired (expressed as a percentage).
Specificity expresses that calculator's ability to correctly classify children as typically developing (expressed as a percentage).
REPORTING THE RESULTS OF THE CALCULATORS
The results of the Language Development Calculators are reported differently than individual test scores. This is because:
The probability score is calculated based on examining a combination of test scores, each with different weightings.
ELL Children's length of exposure to English is included in the calculation (as opposed to monolingual children, for whom age is equivalent to exposure).
Test scores are compared ("norm-referenced") to two comparison groups: typically-developing ELL children and ELL children with language impairment/developmental language disorder.
Here is an example description of how the probability score was obtained and what it means, for reporting purposes:
The child's scores from a group of tests, __________, together with the child's length of exposure to English, were entered into a binary logistic regression formula. Where available, standard scores were entered to take into account the child's age. The formula calculated the probability of that child's test scores patterning like ELL children with typical development as compared to ELL children with language impairment/developmental langauge disorder. This calculation is a form of norm-referencing to an ELL comparison group across several tests in combination. The probability score __________ can be interpreted as follows:
A score of 0-.49 indicates a low probability of the child having language impairment/developmental language disorder
A score of .50-1.0 indicates a high probability of the child having language impairment/developmental language disorder
Peabody Picture Vocabulary Test
The PPVT is a measure of receptive vocabulary size where children are given an array of four pictures and must point to the one that matches the word spoken by the test administrator. The test must be administered and scored according to the published instructions.
Administering the PPVT takes approximately 15 minutes. An additional 5 minutes is required for scoring and calculating scores.
Scores from the more recent versions of the PPVT correlate closely with scores from earlier versions; entering scores from a later version will work for the purposes of the calculator.
REFERENCE
Dunn, L. and Dunn, L. (2007). Peabody Picture Vocabulary Test IV. Pearson.
Test of Early Grammatical Impairment
The Test of Early Grammatical Impairment (TEGI) is a standardized test of grammatical ability. It includes probes that require the child to produce English words in sentences with target grammatical morphemes. For the identification of language impairment on this website, only the scores from the TEGI Screening Test are used. The Screening Test consists of three sub-tests from the TEGI
The Phonological Probe is used to verify that children are capable of producing the word-final consonants that are being tested.
The Third Person Singular Probe tests children's ability to produce -s, as in she plays and he sings.
The Past Tense Probe tests children's ability to produce regular and irregular past tense forms, as in he played and she gave.
For each of these probes, the child describes pictures using certain grammatical forms that are elicited through specific prompts. A Screening Test score is calculated by combining results of both probes.
Administering the TEGI Screening Test takes approximately 10-15 minutes. This includes writing down a child's responses. An additional 10-15 minutes is required for scoring and calculating scores.
TEGI Materials:
NB: TEGI scores should be proportions, not percentages for the calculator (see above)
REFERENCE
Rice, L. & Wexler, K. (2001). Test of Early Grammatical Impairment. United States: The Psychological Corporation: A Harcourt Assessment Company.
Comprehensive Test of Phonological Processing
The Comprehensive Test of Phonological Processing (CTOPP) consists of several subtests. For the identification of language impairment on this website, only the scores from the Nonword Repetition subtest are used.
During the Nonword Repetition task, a recording of several made up words is played from the computer and children are asked to repeat the words as accurately as possible after hearing them once. The test begins with basic one-syllable nonce words and continues with increasing complexity.
Administering the CTOPP takes approximately 5-10 minutes. An additional 15-30 minutes is required for listening to responses and calculating scores.
Scores from the more recent versions of the CTOPP Nonword Repetition correlate closely with scores from earlier versions; entering scores from a later version will work for the purposes of the calculator as long as the standard scores are on the same scale (mean of 10; SD of 7-13).
Instructions and scoring for the CTOPP version used for this study can be downloaded here. Words will need to be read aloud, instead of being played from a recording.
Responses to this probe might be difficult to write down or score while administering the test. It is recommended to record the responses to listen to them later for the most accurate scoring.
REFERENCE
Wagner, R., Torgesen, J., and Rashotte, C. (1999). Comprehensive Test of Phonological Processing. Pearson.
Edmonton Narrative Norms Instrument
The Edmonton Narrative Norms Instrument (ENNI) is a tool for collecting structured language production samples from children aged 4 to 9 through storytelling activities. The ENNI consists of two sets of three-story picture books from which children tell a total of six stories. The picture books increase in complexity by adding characters and making story action more involved. A child tells the stories to the examiner, who cannot see the pictures, so the child cannot use strategies like joint attention or gestures like pointing.
The ENNI and accompanying manual with instructions for administration, transcription and analysis are available for free download from the ENNI website.
Administering the ENNI takes approximately 30 minutes. The transcription of 6 stories takes from 45 minutes to an hour. Scoring and analyzing all measures takes an additional 45 minutes to an hour. Analyzing just the three measures required for using the calculator takes approximately 15-25 minutes. These measures are Story Grammar for Narrative (A3), Mean Length of Communicative Unit (MLCU) and Number of Different Words (NDW).
REFERENCE
Schneider, P., Dubé, R.V., and Hayward, D. (2005). Edmonton Narrative Norms Instrument. University of Alberta.