Conventional approaches for selecting a reference indicator (RI) could lead to misleading results in testing for measurement invariance (MI). Several newer quantitative methods have been available for more rigorous RI selection. However, it is still unknown how well these methods perform in terms of correctly identifying a truly invariant item to…

The piecewise latent growth models (PWLGMs) can be used to study changes in the growth trajectory of an outcome due to an event or condition, such as exposure to an intervention. When there are multiple outcomes of interest, a researcher may choose to fit a series of PWLGMs or a single parallel-process PWLGM. A comparison of these models is…

We explore the following two cognitive questions regarding crosslinguistic variation in lexical semantic systems: Why are some linguistic categories--that is, the associations between a term and a portion of the semantic space--harder to learn than others? How does learning a language-specific set of lexical categories affect processing in that…

In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

Within the discussion of the development of commonsense theories of motion, recent research has established that throughout middle childhood, reasoning about motion down inclines changes with increasing age. To investigate this shift in more detail, this study investigated 5- to 11-year-old children's understanding of motion down curved slopes,…

Numerical comparison is a primary measure of the acuity of children's approximate number system. Approximate number system acuity is associated with key developmental outcomes such as symbolic number skill, standardized test scores, and even employment outcomes (Halberda, Mazzocco, & Feigenson, 2008; Parsons & Bynner, 1997). We examined…

Young children can quickly and intuitively represent the number of objects in a visual scene through the Approximate Number System (ANS). The precision of the ANS--indexed as the most difficult ratio of two numbers that children can reliably discriminate--is well known to improve with development: whereas infants require relatively large ratios to…

This quantitative causal-comparative study investigated the growth performance scores of English learners in grades three through five in reading, mathematics, and science in four English language educational programs: English as Second Language (ESL), Transitional Bilingual Education (TBE), Dual-Language Immersion (DLI), and No Services. I used…

The effects of family adverse childhood experiences (ACEs) on timing of ASD diagnoses and receipt of therapies were measured using data from the 2011-2012 National Survey of Children's Health. Parametric accelerated failure time models estimated the relationship between family ACEs and both timing of ASD diagnosis and receipt of therapies among US…

In this article, I argue that first language (L1), second language (L2) and third language (L3) acquisition are fundamentally the same process, based on learning by parsing. Both child and adult learners are sensitive to fine linguistic distinctions, and language development takes place in small steps. While the bulk of the article focuses on…

Purpose: Childhood stuttering is common but is often outgrown. Children whose stuttering persists experience significant life impacts, calling for a better understanding of what factors may underlie eventual recovery. In previous research, language ability has been shown to differentiate children who stutter (CWS) from children who do not stutter,…

Many interventions are characterized by repeated observations on the same individuals (e.g., baseline, mid-intervention, two to three post-intervention observations), which offer the opportunity to consider differences in how individuals vary over time. Effective interventions may not be limited to changing means, but instead may also include…

Age of acquisition (AoA) is a measure of word complexity which refers to the age at which a word is typically learned. AoA measures have shown strong correlations with reading comprehension, lexical decision times, and writing quality. AoA scores based on both adult and child data have limitations that allow for error in measurement, and increase…

The ability to mentally re-experience past events improves significantly from childhood to young adulthood; however, the mechanisms underlying this ability remain poorly understood, partially because different tasks are used across the lifespan. This study was designed to address this gap by assessing the development of event-related potential…

There is considerable variability in the extent to which young people with developmental language disorder (DLD) experience mental health difficulties. What drives these individual differences remains unclear. In the current article, data from the Twin Early Development Study were used to investigate the genetic and environmental influences on…