Standardisation

Question 1

Standardisation

Answer 1

The meaning of test scores derives from the frames of reference we use to interpret them & from the context in which the scores are obtained

Standardisation refers to the need for uniformity in all procedures while using a valid & accurate test

Question 2

Standardised test

Answer 2

Same test given in same manner to all test takers & graded in same manner for everyone

Designed in such a way that the questions, conditions for administrating, scoring procedures & interpretations are consistent & administered & scored in predetermined, standard manner

Question 3

Raw score

Answer 3

A raw score is a number (X) that summarises or captures some aspect of persons performance in carefully selected & observed behaviour samples that make up psych tests

Raw score doesn’t convey any meaning by itself

Question 4

Norm

Answer 4

Created with scores from respondents who participated in normative study

Expected to be drawn from representative sample (normative group)

Question 5

Norm-referenced tests

Answer 5

Norms usually presented in form of tables with descriptive stats that summarise performance of groups or groups in question

When norms are collected from test performance of groups of people, these reference groups are labelled normative or standardised samples

Norms typically created from calculation of percentiles & standard scores

Mean & SD are main stats used to create norms

Question 6

Norm-referenced tests continued

Answer 6

Norms most widely used frame of reference for interpreting test scores

Used for test takers comparison

Score used to place test takers performance within a pre-existing distribution of scores or data obtained from performance of suitable comparison group

These scores can be obtained by linear/non-linear transformations of obtained data

Question 7

Linear transformations or non-normalised standard scores

Answer 7

Linear transformation changes units in which scores expressed while leaving interrelationships unaltered

Shape of linearly derived scale score distribution for given group of test takers is same as that if original raw score distribution

Question 8

Z-scores

Answer 8

Non-normalised standard score (linear)

Transforms original scores of group measures in units of SD

Normally distributed scores of tests with different means, standard deviations & score ranges can be meaningfully compared once they have been linearly transformed into common scale as long as same reference group used

Question 9

T-scores

Answer 9

Non-normalised standard score (linear)

Same purpose as z-scores, with advantage of eliminating negative numbers & decimal numbers

Question 10

Non-linear transformations or normalised standard scores

Answer 10

Normalised standard scores are those that concert a raw score distribution that has different shape than original

Raw scores not completely normal but are made normal

Question 11

Percentile (PR)

Answer 11

Normalised standard score (non-linear)

Indicates the value below which a given percentage of observations in a group of observations fall

Higher percentile scores indicate higher raw scores

Question 12

Percentile advantages

Answer 12

Easy to calculate & can be clearly understood even by people with no training

Suitable for any type of test

Question 13

Percentile disadvantages

Answer 13

In a Normal distribution the majority of scores tend to cluster around a central value & scatter more widely at the extremes, making percentile score units markedly unequal at different points of the range

Percentiles show relative position of each individual in normative sample, but not the amount of difference between the scores

Any given difference in percentile rank score units magnifies the apparent discrepancy in the relative performance of individuals whose scores are in middle range & compresses the apparent extent of the difference in the relative performance of individuals at high & low ends of distributions

Question 14

Criterion-referenced tests

Answer 14

In realm of educational & occupational assessment, tests are often used to help ascertain whether a person has reached certain level of competence in field of knowledge or skill in performing task

Instead of comparing performance to others, performance is compared to predetermined criterion or standard

Question 15

Criterion

Answer 15

Criterion may refer either to knowledge of specific content domain or to competence in some kind of endeavour

Standards by which criterion-referenced tests are evaluated are typically defined in terms of specified levels of knowledge or expertise necessary to pass a course, obtain a degree etc, may also involve demonstration of sufficient competence to do job or create product

Question 16

Norm vs criterion referenced tests

Answer 16

In norm-referenced testing, primary objective is to make distinctions among individuals or groups in terms of ability or trait assessed by test

In criterion-referenced testing, primary objective is to evaluate a person or groups degree of competence or mastery of skill or knowledge domain in terms of pre-established standard of performance