Which Test, and When? A Preschool Assessment Guide

"Which test should I use?" is rarely the right first question. The useful one is "what do I need to know about this child right now?" The question selects the instrument; the instrument never generates the question. What follows is a decision path for the years before school entry, organised by age band.

Screening and assessment are different jobs

The two words get used interchangeably in conversation, but they do different clinical work.

• Screening is fast, applied broadly, and answers one question: is there something here worth a closer look? It tolerates false positives, because its job is to miss nothing.
• Assessment comes afterwards and answers a narrower question in depth: what exactly is going on? It is longer, requires a trained administrator, and covers less ground more thoroughly.

Developmental checklists and the Ankara Developmental Screening Inventory sit on the screening side. The Peabody Picture Vocabulary Test, Bender-Gestalt and the Metropolitan Readiness Test sit on the assessment side. Reversing the order — opening with a long performance measure before anything has been screened — costs time and tires the child for no gain.

A map by age band

The table below pairs each band with the question that usually comes first and the kind of tool that answers it.

Age	First question	Suitable tool type
0–2 years	Are the basic milestones arriving on time?	Caregiver-report developmental screening; autism screening around 18–24 months
2–3 years	Has the language burst and motor independence started?	Age 2 developmental checklist, M-CHAT
3–4 years	Are social participation and self-care age-appropriate?	Age 3 and age 4 checklists
4–5 years	Is receptive language behind that of peers?	Picture vocabulary measures
5–6 years	Is this child ready for school?	Age 5 checklist, age 6 readiness checklist, a readiness test
5–7 years	Is visual-motor maturity sufficient for writing?	Gesell figures, Bender-Gestalt

What observation tools add

A developmental checklist is not administered to the child; it is completed by an adult who knows the child well. That is a different source of information rather than a weaker one. A performance test shows the best a child can do in a single session; an observation checklist shows what the child does reliably in everyday life. When the two disagree, the disagreement itself is clinical information — a skill demonstrated with a clinician but never in the classroom shifts the question from "can they?" to "why don't they?"

When to refer on

One low score is not a referral. The patterns that warrant a closer look are:

• Delay in more than one developmental domain at the same time
• Loss of a previously established skill — regression justifies prompt assessment at any age
• A large, repeated mismatch between observation and performance
• Persistent concern from a parent or teacher, even with scores in the expected range

Three mistakes that recur

1. Using class year instead of age. Two children in the same group can be eleven months apart, which is enormous before school. Interpretation is always anchored to age in months.
2. Deciding on one session. A tired, hungry or newly anxious child does not perform at their own level.
3. Presenting a screen as a diagnosis. Screening quantifies; diagnosis weighs history, functioning and alternative explanations.

A case: one sentence, three routes

Three families open with the same line: "The teacher asked us to have their development checked." The same sentence produces three different pathways.

A, 32 months. The family reports no speech yet. The priority is language and social communication: a developmental checklist for the overall picture plus an autism screen. With no motor concern, no performance test is needed.

B, 50 months. The family reports a poor pencil grip and no interest in colouring. The focus is fine and visual-motor skill — but the prior question matters more: is the child refusing these tasks or attempting and failing? If refusal dominates, motivation or anxiety comes before skill, and a test run without that distinction will be misread.

C, 68 months. The family asks whether to start school in the autumn. That is a decision question, not a screening one. It needs a readiness picture across four domains plus observation data; no single subtest can carry it.

Conditions that invalidate a result

• Time of day. A session scheduled over a nap measures fatigue, not ability.
• Sensory status. If vision and hearing have not been checked, weak performance may be sensory rather than developmental. This step is skipped surprisingly often.
• Language history. Where another language is spoken at home, low scores on verbal tasks may reflect exposure rather than capacity.
• Recent change. A new sibling, a move or a change of nursery temporarily depresses the social-emotional domain.

What comes next

Choosing tools is only half the work; combining several sets of results into one coherent picture is a separate skill, covered in how to build a test battery. For the school-entry decision specifically, see what school readiness is and how it is measured.

Frequently asked questions

Is a developmental test the same as an intelligence test?

No. Developmental tools track whether specific skills have been acquired; intelligence measures place cognitive performance against standardised norms. Before school, cognitive testing is usually unnecessary, and results obtained very early are not stable over time.

Will a low score label my child?

The output of a screen is a direction, not a label. It says "let us look at this area more closely", and reporting should preserve that framing.

Can the same test be repeated soon afterwards?

Observation checklists, yes. Performance tests usually need an interval because of practice effects; if an early repeat is necessary, a different instrument measuring the same domain is preferable.

The teacher and the parent gave different answers. Who is right?

Both. Behaviour varying by setting is itself a clinical finding, and often one of the most useful things you learn.

This article is for information only. The scales and tests mentioned here are screening and assessment instruments; on their own they do not establish a clinical diagnosis. Administration and interpretation belong to licensed professionals trained in the relevant instrument. Item texts, stimulus cards, and norm tables of copyrighted tests are never published on this page.