This is an indicator of the amount of dispersion in a score distribution. To calculate variance, the difference of each score from the mean is squared. Then all the squares are added together and divided by the number of scores.


The dispersion of values from the average. Standard deviation and variance are measures or variability.

Value Added

This refers to the contribution a school makes to the education of its pupils. If one or more pupils scores higher in National Tests, GCSE or A Level than would have been predicted on the basis of their known earlier level of achievement, the difference is attributed to ‘value-added’ by the school. The concept is usually linked with baseline assessment, since the latter is required to establish the entry level from which the subsequent performance may be judged. Another link is with the term ‘Effective School’, used to designate well-run school which are measurably improving the prospects of their pupils, by adding value.


A valid assessment measures what it claims to measure. Evidence may be presented in various ways – satisfactory correlations with other assessments of the same abilities or skills; or with teaches’ estimates of their pupils’s abilities; or with pupils’ subsequent achievements such as their results in a public examinations.


Test Battery – see Battery

Teacher Assessment

This can take many forms – such a summative or formative assessment, which may include publishing tests. In the context of the National Curriculum, and the 5-14 Guidelines in Scotland, it is usually used to mean any form of assessment carried out by the teacher, other than the National Tests prescribed by the Government.

Summative Assessment

This is used for the recording of the overall achievement of a pupil in a systemic way. It occurs at the end of a scheme of work or phase of education, and a norm-referenced assessment is often used for this final summing up of performance.


A stanine (which is abbreviated from ‘standard nine’) is a standard score scale ranging from 1 to 9. Stanines are simple to use and place small difference of score in perspective. Stanines have a mean of 5 and a standard deviation of 2.

Standardised Test

A standardised test will have been administered to a representative sample of a defined population in order to calculate norms. Norms give information about the performance of this sample. By using the norms as a reference points, teachers can compare the performance of their pupils with the standardised sample. A test can also have standardised administration procedures, whereby strict instructions have to be followed by the administrator.

Standard Error of Measurement (SEM)

The estimate of the ‘error’ associated with pupils’ obtained score when compared with their hypothetical ‘true’ score. The SEM, which varies from test to test, should be given in the test manual. The band of scores in which we can be fairly certain the ‘true’ score lies, can be calculated from these figures. For example, we can be 95 per cent certain that a pupils’ true score lies in the range ‘obtained score plus or minus 2 SEM’ and 99 per cent certain that it lies in the range ‘obtained score plus or minus 3 SEM’.

Standard Deviation

A way of expressing how much a normally distributed sample of scores is spread out. Nearly all of any sample of scores are contained in the range Mean plus or minus 3 Standard Deviations.

Standard Assessment Tasks (SAT’s)

The name formerly given to the statutory National Tests in England, Wales and Northern Ireland.

Standard Age Score or Standard Score

A standard score scale in which the mean score for each age group on an assessment is set at 100 and the standard deviation at 15. For any age group a given numerical value has the same meaning in terms of standing relative to the group. For example, an eight-year-old and a nine-year-old, each of whom has a standard age score of 105, have performed equally well in relation to the average for their respective age groups.


A test’s reliability concerns the consistency with which it measures whatever it is supposed to be measuring. A reliable assessment is dependable and will yield similar results each time it is used. Perfect reliability is represented by reliability coefficient of 1.0 but in practice this is never achieved although figures upwards off about 0.85 are commonly obtained.

Record of Achievement

A report on an individual child’s learning and development, compiled by the school. The report includes details of child’s progress in relation to the National Curriculum in England, Wales and Northern Ireland, and the 5-14 Guidelines in Scotland, but also reports on other aspects of the child’s overall experience of education.

Reading Age

This tells you the current developmental level of a child’s performance in a particular area of reading, such as comprehension, or word recognition skills. For example, a nine-year-old child with a reading age of nine is performing at the national average level for his or her age. Another child aged nine years, with the reading age of 10, is developmentally 12 months ahead of his or her peers in reading.

Raw Score

A score on assessment which is expressed simply as a total of the marks obtained on the test.


Literally, pertaining to mind and language. The study of mental processes that underlie the acquisition and use of language.


A profile based on assessment results, which provides a clear visual check on each child’s performance in an assessment or a series of assessments.  It enables strengths and needs to be easily identified. Performance in successive testing can be compared and skills can be contrasted with abilities.

Predictive Validity

Extent to which a test predicts ability in the same or similar areas in the future. For example, a test might be correlated with examination success (usually expressed in the terms of a correlation coefficient).


Off speech sounds.   


Used as a term to cover the knowledge and teaching of grapheme-phoneme correspondences.


Speech sounds.


This type of score indicates the percentage of children in an age group who obtained scores below a particular score. For example, pupil with a percentile rank of 70 has a score which was as good as or better than 70 per cent of the normative sample for his or her age group. Note that a child’s percentile on an assessment should not be confused with the term ‘percentage’ which indicates the proportion of assessment items correctly answered.

Parallel Forms

Alternative assessment forms which differ in content but are off the same level of difficulty and provide equivalent standardised scores. These are particularly useful for retesting, where it may be inadvisable to use an identical assessment on the second occasion because of the effects of practice and memory. Parallel forms also help prevent copying during assessment sessions.

Objective Assessment

An assessment whose precise answers have been agreed and which can be objectively and reliably marked using a scoring key or an automated scoring system.

Norm-Referenced Assessments

This is a method of assessment whereby pupils obtained standardised scores that allow their individual performance to be compared with that of their age-related peers. These scores are provided in norm tables, which take age into account. Information obtained from norm-referenced assessment is particularly useful for comparing the performance of individuals with the national average; this allows standards to be monitored on a national basis.

National Tests

The name given by the DfEE and QCA to the statutory tests in the Core and Foundation subjects of the National Curriculum, taken by all children in Local Authority schools in England, Wales and Northern Ireland at the end of Key stage one to three (ages 7, 11 and 14 in England and Wales). They are sometimes referred to as ‘SATs’ (Standard Assessment Tasks), the original equivalent tests in the early years of the National Curriculum.

Narrative Assessment

An assessment that ranks an individual’s level of performance in relation to the performance of others of the same age.

Miscue Analysis

A way of acquiring inside into children’s reading strategies by studying the mistakes they make (their miscues) whilst reading aloud. By considering the pattern of the miscues made, the teacher may gain more insight into possible strategies for teaching.

Mental Age

The age corresponding to the chronological age of individuals who score at the Mean for a specified test. Through standardisation it is possible to calculate the mental age for a child who is much older but scores below the Mean, or for a child who is much younger and scores above the Mean.


The middle number in a series of numbers arranged in order of magnitude.


Arithmetical average.

Ipsative Assessment

An individual’s strengths and weaknesses are made apparent by contrast and congruencies within his or her pattern of responses.

General Conceptual Ability (GCA)

The general ability of an individual to perform complex mental processes involving conceptualisation and transformation of information.

Formative Assessment – see also Summative Assessment

An ongoing assessment which is used to highlight a particular child’s strengths, needs and potential. Information gained from formative assessment can be used when discussing and devising the next steps for that child’s development. A criterion-referenced assessment is often used for formative assessment.


Speech disorder associated with muscle spasms and clumsiness.


Impaired co-ordination of speech.


Seen primarily as a limitation in the ability to deal with symbolic materials.


A speech disorder related to impaired muscular control of the speech mechanisms.

Down’s Syndrome

A genetic condition caused by extra genetic material from the 21st chromosome. The extra genes cause certain characteristics that are recognised as Down’s Syndrome, but individuals with the condition will also have all the other genes given to them by their parents. This results in the combination of futures typical of Down Syndrome on top of the individual features from their parents. This includes some degree of cognitive disability and other developmental delays. Some of the physical traits that are common, but are not always present, or epicanthal folds over the eyes, flattened bridge of the nose, a single palmar crease and decreased muscle tone.

Diagnostic Assessment

A diagnostic assessment identifies a pupil’s underlying strengths and needs in a particular area. Such an assessment may be able to explain why a child is experiencing a specific learning difficulty and can help teachers evaluate the severity of the problem. This information will prove invaluable when devising future teaching programmes.

Criterion-Referenced Assessment – see also Norm-Referenced Assessment

A criterion-reference assessment measures what a child can do against a specified set of objectives or skills. Assessing whether a skill has been mastered will provide useful diagnostic information.

Content Validity

The extent to which a test contains items which are representative of the domain to be measured.

Construct Validity

The extent to which a test may be said to measure that which it has been designed to measure. This is a matter of judgement, based on accumulated evidence.

Concurrent Validity

The extent to which a test correlates with other measures or tests which are said to measure the same thing.


Refers to a mental process of reasoning, memory, judgement and comprehension – as contrasted with emotional and volitional processes.

Cloze Procedure

A cloze procedure is a prose passage from which certain words have been deleted and replaced with gaps. The task of the test taker is to supply words for these gaps.


The point at which it is assumed that the subject would not be able to get credit by further testing.


A test battery is a collection of assessments assembled for a specific purpose; all of them standardised on the same population. It provides a wider and more detailed coverage of abilities or skills than can be achieved by a single assessment.

Baseline Assessment – See also Value Added

A standardised test, battery of test, or observational procedure designed to establish the attainment level of children at a significant point, particularly on entry to schools at around five years and transfer to secondary schools at 11 years. Their performance is regarded as a ‘baseline’ from which their subsequent performance may be predicted, monitored and any relative improvement or deterioration judged.

Basal Level

The point at which it is assumed that a subject would have received credit for earlier and easier items in the test.


Autistic spectrum disorder is a developmental disorder characterised by impaired social development. The condition has wide ranging degrees of severity, but those suffering have a ‘triad’ of impairments which affect: social interaction; social communication; and imagination. Repetitive or obsessive behaviour patterns are also a notable feature. The exact cause of autism has not yet been fully established although genetic factors appear to be important.

Auditory Discrimination

The ability to detect a difference between sounds (usually speech sounds) when presented orally.

Attention Deficit Hyperactivity Disorder (ADHD)

A syndrome characterised by persistent difficulties in three specific areas: attention span; impulse control; and (sometimes) hyperactivity. ADHS is a chronic disorder that can begin in infancy and extend trough adulthood with a negative effects on a child’s life at home, school, and within the community.

Attainment Assessment

Assessments designed to measure the level of knowledge or skills already acquired through learning. Traditionally, the content tended to be linked to the recall of facts but nowadays measurement is focused more on broader educational targets and/or on the application of understanding of knowledge and skills.

Aptitude Assessments

Assessments designed to find out the potential to acquire or develop specific skills, such as those approaches used in careers guidance.


Loss or impairment of ability to speak, write or understand the meaning of words, due to brain damage.


Loss or impairment of ability to read, due to brain damage.

Ability Assessments

Assessments designed to find out the level of developed potential at the time of testing in particular aspects of reasoning.