Scale Overview
The Strengths and Difficulties Questionnaire – SDQ (Self-Completion) was developed by Robert Goodman, Harry Meltzer, Valerie Bailey (1998). It is designed to measure Child and adolescent mental health, strengths, and difficulties. The scale is intended for use with Adolescents (approx. 11-17 years).
Scale Structure
This instrument consists of 25 items organized into 5 factors/subscales: Emotional Symptoms, Conduct Problems, Hyperactivity/Inattention, Peer Relationship Problems, Prosocial Behaviour.
| Factor / Subscale |
Items |
N |
| Emotional Symptoms |
3,8,13,16,24 |
5 |
| Conduct Problems |
5,7,12,18,22 |
5 |
| Hyperactivity/Inattention |
2,10,15,21,25 |
5 |
| Peer Relationship Problems |
6,11,14,19,23 |
5 |
| Prosocial Behaviour |
1,4,9,17,20 |
5 |
Response Format
Respondents rate each item using a custom response format.
Response anchors: 0 = Not True, 1 = Somewhat True, 2 = Certainly True.
The scale includes 5 reverse-scored items to reduce acquiescence bias.
Scoring
Items are scored by subscale, with each subscale sum representing a distinct dimension.
Total scores range from 0 to 40. Interpretation guidelines:
- Close to average: 0 – 15
- Slightly raised: 16 – 19
- High: 20 – 40
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of Cronbach's alpha typically ranges from 0.60 to 0.80 for subscales.
Administration
The scale is self-administered and typically takes approximately 5 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.