Purpose: The purpose of this study was to explore the use of language sample analysis and standardized norm-referenced assessment in early childhood intervention research focused on language outcomes. A sample of data from a larger randomized control trial was used to explore interrater reliability between two independent transcribers, provide a description of scores for children with disabilities, calculate estimates of intervention effects, and examine relationships between scores from language sample analysis measures and a standardized norm-referenced assessment. Method: Reliability was evaluated using the intraclass correlation coefficient for 33% of the language samples. Children's language sample scores were obtained using the Systematic Analysis of Language Transcripts computer software. Analysis of covariance and calculation of effect size estimates were calculated to determine the effect of the intervention on children's expressive language. Relationships between measures were evaluated using Pearson's product-moment correlation coefficients and squared correlation coefficients. Results: All intraclass correlation coefficient estimates for consistency and absolute agreement were 0.96 or greater indicating reliability between two independent transcribers across all language sample analysis measures. Descriptive statistics provided information about the children's expressive language skills on average at pre-intervention and post-intervention. One statistically significant and noteworthy effect was identified for the onsite coaching condition vs. business-as-usual condition for number of total words used in a language sample. Language sample analysis measures and the standardized norm-referenced assessment shared moderate variance. Implications: Establishing reliability is important for meaningful interpretations of the research questions. Language sample analysis scores provided information about the language skills of children with various disabilities (i.e., developmental delay, speech language impairment, speech impairment, language impairment, hearing impairment, autism, Down syndrome, cerebral palsy). Statistical significance and effect size estimates provided information about the magnitude of effect of an intervention on children's expressive language skills. The shared variance found between the different measures suggests that for children with disabilities, a relatively consistent picture of language abilities can be obtained from both structured administration of a standardized norm-referenced assessment and from language sample measures derived from structured play-based interactions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]