Scientific background: Attachment Style
About this test
The ECR-R was developed in 2000 by Fraley, Waller, and Brennan using item response theory, based on the original ECR by Brennan, Clark, and Shaver (1998), and is considered one of the psychometrically most robust instruments in attachment research. The combination of low attachment anxiety and low attachment avoidance is referred to in the research literature as a "secure attachment style"; high scores on one or both dimensions correspond to anxious-insecure, avoidant-insecure, or anxious-avoidant attachment patterns.
Dimensions
Attachment Anxiety
The degree of worry about being rejected or abandoned by a partner.
Attachment Avoidance
The degree of discomfort with emotional closeness and depending on partners.
Sources & license
Fraley, R. C., Waller, N. G., & Brennan, K. A. (2000). An item response theory analysis of self-report measures of adult attachment. Journal of Personality and Social Psychology, 78(2), 350–365.
Per the original author R. Chris Fraley's own published statement, "the scales were published in a scientific journal for use in the public domain. You do not need to contact any of the authors for permission to use these scales in non-commercial research." A free, non-commercial self-assessment site fits this framing, though Fraley's wording is scoped to "non-commercial research" specifically -- his own site asks to be contacted before commercial use. Item wording, response-scale anchors, and reverse-scored items were verified verbatim against Fraley's own published item list and scoring instructions.
https://labs.psychology.illinois.edu/~rcfraley/measures/ecrr.htm