Licences and attribution

Every instrument lists its licence, its source, and the paper that describes it. A test enters this site only when its licence permits public use.

Anxiety screen (GAD-7)

Field	Value
Licence	Public domain
Licence notes	The GAD-7 is in the public domain. No permission is required to reproduce, translate, display, or distribute it.
Citation	Spitzer, R. L., Kroenke, K., Williams, J. B. W., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: The GAD-7. Archives of Internal Medicine, 166(10), 1092-1097.
Source	https://www.phqscreeners.com/

Spitzer, R. L., Kroenke, K., Williams, J. B. W., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: The GAD-7. Archives of Internal Medicine, 166(10), 1092-1097. doi:10.1001/archinte.166.10.1092
Pfizer (2026). Instructions for Patient Health Questionnaire (PHQ) and GAD-7 measures. https://archive.thepcc.org/sites/default/files/resources/instructions.pdf.

Field	Value
Licence	Public domain
Licence notes	The IPIP items are in the public domain. Copy, edit, translate, and use them for any purpose without permission and without a fee.
Citation	Johnson, J. A. (2014). Measuring thirty facets of the Five Factor Model with a 120-item public domain inventory: Development of the IPIP-NEO-120. Journal of Research in Personality, 51, 78-89.
Source	https://ipip.ori.org/30FacetNEO-PI-RItems.htm

Johnson, J. A. (2014). Measuring thirty facets of the Five Factor Model with a 120-item public domain inventory: Development of the IPIP-NEO-120. Journal of Research in Personality, 51, 78-89. doi:10.1016/j.jrp.2014.05.003
Goldberg, L. R. (1999). A broad-bandwidth, public domain, personality inventory measuring the lower-level facets of several five-factor models. Personality Psychology in Europe, 7, 7-28.
International Personality Item Pool (2026). IPIP item pool and scales. https://ipip.ori.org/.
International Personality Item Pool (2026). Information about Norms and Data Sets. https://ipip.ori.org/newNorms.htm.

Field	Value
Licence	Public domain
Licence notes	The IPIP items are in the public domain. Copy, edit, translate, and use them for any purpose without permission and without a fee.
Citation	Goldberg, L. R. (1992). The development of markers for the Big-Five factor structure. Psychological Assessment, 4(1), 26-42.
Source	https://ipip.ori.org/New_IPIP-50-item-scale.htm

Goldberg, L. R. (1992). The development of markers for the Big-Five factor structure. Psychological Assessment, 4(1), 26-42. doi:10.1037/1040-3590.4.1.26
International Personality Item Pool (2026). Big-Five Factor Markers scoring key. https://ipip.ori.org/newBigFive5broadKey.htm.
International Personality Item Pool (2026). IPIP item pool and scales. https://ipip.ori.org/.

Field	Value
Licence	Public domain
Licence notes	The PHQ family, including the PHQ-9, is in the public domain. No permission is required to reproduce, translate, display, or distribute it.
Citation	Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606-613.
Source	https://www.phqscreeners.com/

Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606-613. doi:10.1046/j.1525-1497.2001.016009606.x
Spitzer, R. L., Kroenke, K., Williams, J. B. W., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: The GAD-7. Archives of Internal Medicine, 166(10), 1092-1097. doi:10.1001/archinte.166.10.1092
Pfizer (2026). Instructions for Patient Health Questionnaire (PHQ) and GAD-7 measures. https://archive.thepcc.org/sites/default/files/resources/instructions.pdf.

If an attribution is wrong or incomplete, open an issue at github.com/frsswq/personality-test/issues. The item text, the scoring key, and the site code are public.