SLPs are pretty dynamic people. We perform evaluations in languages we don’t speak, identify and bridge cultural barriers, and change lesson plans on a dime to follow our English-language learner (ELL) students’ teachable moments. SLPs who work with clients from various cultural and linguistic backgrounds need a collection of soft skills that make our profession an art form.
We should also remember what we do is a science. We apply scientific principles when we make, rule out and confirm hypotheses to assess clients’ needs. To do that we collect objective data and analyze and interpret it. It’s tough to feel like a scientist in a room of preschoolers, but keeping that role in mind makes us stronger practitioners. One scientific principle discussed in the area of psychology, “converging evidence,” particularly helps in assessing cultural and linguistic influences.
Let’s explore this with a few key terms and examples:
Converging evidence means we should make clinical judgments based on the majority of evidence. In other words, we look at all the evidence together, examine how data interact and determine what the “big picture” tells us.
Connectivity says a theory qualifies as an “advance” only if it explains old information and identifies new information. For SLPs, it’s not enough to use one good test score as an indicator that our client no longer needs services. We must also account for why the client performed poorly on other tests, what changed if they were previously eligible, or where client/family/professional concerns originated.
Logic of flawed experiments tells us there’s no such thing as a perfect test. Standardized, criterion-referenced and curriculum-based testing, as well as observations and other informal tests, all contain susceptibility to bias and error. However, when tests flawed in different ways point in the same direction, it increases our confidence in the conclusion they lead us to draw. And this gives us one solid reason we shouldn’t rely on any single testing instrument. It also demonstrates why we need to use a variety of data sources and not formal assessments exclusively.
Theory evaluation means a single theory receives support only to the extent of others getting ruled out. It gives us a mechanism to understand how most areas of science contain multiple, competing theories. In the case of an English-learning child, the data telling us she has an impairment are only as useful as the data telling us what we see isn’t just a difference.
Although they might not all use the term converging evidence, some of our colleagues’ work showcase how to use the idea in service delivery:
- Cate Crowley’s Leaders Project features wonderful video learning modules demonstrating converging evidence in action with preschool and school-age assessment. They also present a variety of model speech-language reports.
- Brian Goldstein reviews how to use a variety of assessments to assess phonology in bilingual children.
- Brenda Gorman and Alejandro Brice’s TESELL project offers learning modules addressing a variety of issues, including the use of converging evidence to assess English-language learners.
We may wear the stains of preschool circle time instead of a lab coat, but our need for the scientific method and converging evidence remains the same! How do you use these principles in your practice? Share your ideas in the comments section below.