### Appendix C (Coder Design Effect)

The coder design effect (deffc) applies much of the same logic as the interviewer design effect (see Interviewer Recruitment, Selection, and Training) .

• In the following formula for coder design effect, $$\rho_{c}$$ is the intraclass coefficient for coders, $$m$$ is the average number of cases coded per coder, and $$r$$ is the reliability of a particular (item) code: $$\text{deff}_{c}=1+\rho_{c}(m-1)(1-r)$$.
• The intraclass coefficient for coders is a measure of the ratio of coder variance to the total variance and is defined as $$\rho_{c}=\frac{\text{between-coder variance}}{\text{between-coder variance}+\text{within-coder variance}}$$.

Reference