What is What Works?
Who is What Works for?
Why should I use What Works?
How do I use What Works?
How do I submit an intervention?
Get involved in What Works
Understanding the evidence base
The SEND Code of Practice
Glossary of terms
What Works Training Database
Please find below definitions of some of the terms used in
What Works. Explanations are also available of the
search terms and
levels of evidence.
Articulation, motor speech or speech production
Speech production is the ability to produce sounds. A speech
production difficulty occurs when mistakes continue past a certain
age. These difficulties can include problems with articulation
(making sounds) or motor speech difficulties which includes
dysarthia and dyspraxia.
A term used to define the provision of additional support for
children with speech, language and communication needs over and
above what they would otherwise receive in the class or
How words are represented (and stored) in a model of speech and
The system of the internal structure of words (morphology) and
the way in which words are put together to form phrases and
These are principles based on an understanding of how the
nervous system and muscles work together to support movement.
The study of meaning in language. Semantics is important for
understanding language in social contexts, as these are likely to
affect meaning, and for understanding varieties of English and
effects of style.
Sensory, motor, and phonological impairment
This is a difficulty, affecting a child's sound system which
arises from difficulties with the sensory and motor aspects of
speech. For example with sensing touch, strength, control and range
of movement of parts of the body involved in speech.
This describes the component parts of speech and includes
respiration (breathing), phonation (making sound), resonance (the
quality of sound), prosody (for example intonation, rhythm and
stress) and articulation.
A term used in research methodology; people involved in the
project, which can include participants, investigators or
assessors, who are unaware of the details of the project. For
example, whether people are in a control or experimental group. The
aim is to reduce any bias this knowledge would bring.
This term is used in research where there are a group of
subjects, very similar to the treatment or experimental group
subjects, but without receiving the intervention. This allows a
comparison to be made once results have been gathered.
This is the extent to which a piece of research appears to
measure what it has intended to measure.
Indicative evidence level
Indicative evidence is the lowest evidence level in theWhat
Worksguidance (further information aboutWhat Workswill follow
shortly). It refers to interventions that have some, though limited
research evidence, such as case studies or before and after
studies. Also included as indicative are interventions extensively
used by therapists who have limited research evidence.
Shows positive results for either certain children or certain
aspects of language and less positive results for other
Multiple baseline design
This style of research involves measurement of lots of people or
characteristics both before and after treatment
An evaluation of an intervention by a person or people from the
An experiment which compares different groups of participants on
some measure, with group membership usually manipulated by the
researcher. Participants aren't randomly allocated to groups as
with experimental methodology.
Randomised control trial (RCT)
An experimental design used for testing the effectiveness of a
new medication, a new procedure or intervention. Individuals are
assigned randomly to a treatment group and a control group and the
outcomes are compared.
A high level overview of research around a specific research
question, that aims to gather the evidence related to that research
question in order to answer it.