A tailored calendar method was used to collect retrospective data from hard-to-reach populations: people with very low levels of income, education and literacy that live in complex societal situations and have low trust in authorities. Recognizing the serious threats to data quality in surveying these populations, the presumed helpful graphical display and aided recall properties of calendar interviewing was supplemented by allowing ‘third persons’ to help the respondents.

The subjects of the study are households who were involuntarily displaced and relocated by national governments due to man-made natural disaster and development projects. The site of the present study is in the Philippines, involving 6,144 households whose residency in the relocation site spans from one to 12-year period. A sample of 150 households was randomly selected from the master list of the supervising housing agency.

A tailored calendar method was designed, involving a standardized, face-to-face, retrospective interview with the head of household about the rebuilding of the households’ “social capital” since resettlement. About one-third of the respondents is interviewed with help from ‘third persons’ (e.g. spouse, children, neighbours), while the rest is interviewed without such help. Characteristics of the ‘third persons’, respondents and households are related to the impact of the calendar procedure.

Multiple indicators are used to assess the quality of the data obtained - e.g., “don’t know” and “not yet experienced” responses, completeness of information, rounding and heaping of numbers and dates, and evaluations by respondents and interviewers. The results will yield insights into what procedures can ‘help’ in collecting reliable data from the very hard-to-reach populations.