- Helps in categorizing or diagnosing

- Necessary to determine if therapy is useful

- May reveal specific motor dysfunctions

- Provides sound basis for planning intervention

- Positioning of child

- Amount of physical support

- Verbal cues and physical prompts

It allows the child's development to be compared to same-aged peers

- Large, representative group which serves as a standardization sample for the test

- Children must be tested from:

• A variety of socio-economic classes
• Ethnic groups which are represented nationally
• Different regions of the country
• Age group covered by the test

- Relates to the reproducibility or consistency of measurements or test scores

- How closely do repeated measurements on the same subject agree

1. Test-retest reliability:  Measures consistency fo a child's performance from day to day or week to week
2. Intra-tester reliability:  Measures one person's consistency in administering and scoring assessment
3. Inter-tester reliability:  Measures consistency of administering and scoring responses between 2 or more test givers

The degree to which a test or assessment actually measures what it purports to measure

- The ability of a test to correctly classify people who have a disease or abnormality

-Number of correct referrals / total number of people with condition

a / (a + c)

- The ability of a test to correctly classify people who do not have a disease or abnormality as being free of that disease or abnormality

- Correct non-referrals / total number of people without disease or abnormality

d / (b + d)