Why the right survey method depends on the target population
Before a research agency starts fieldwork in Sierra Leone, it should decide whether the target population can be reached reliably in person, over the telephone or online. CAPI, CATI and CAWI each provide strengths and distortions. The conditions in Freetown, known in this study context as a coastal capital metropolitan area, may differ from those in Bo, an important southern commercial and educational centre. Designing two city-specific recruitment plans can expose those differences while preserving one consistent research framework.
Design begins with the sample frame. Identify whether eligible respondents can be drawn from mapped dwellings, administrative registers, client records, phone-number frames or authenticated online databases. Each option creates a different set of coverage and nonresponse risks. Research managers should specify the claims they intend to make: city-level description, programme participant feedback or population-representative estimates. The mode must help meet those claims. Changing the interview channel does not rescue a weak frame, and a huge convenience sample remains a convenience sample.
CAPI: when in-person digital interviewing is strongest
Face-to-face digital surveys provide an advantage when sampled units are places rather than contact details. A CAPI team can verify a school, shop, water point, household or health facility in its setting. Interviewers can clarify wording without altering the question and can present consistent showcards if the protocol requires them. That strength comes with practical obligations: listing accuracy, safe transport, translations, device charging and supervisor observations. CAPI should not automatically be treated as nationally representative; the probability of selection still comes from the sample design.
CATI: when interviewer-led telephone surveys fit
Computer-Assisted Telephone Interviewing, or CATI, permits a trained interviewer to administer questions by voice using a calling system or structured digital form. It can be suitable for beneficiaries with verified contact records, existing customers, business contacts and rapid follow-up studies. The major risks are unreachable numbers, shared phones, unequal ownership and short respondent attention spans. A reliable CATI protocol defines call attempts at different times, dispositions, appointments, refusals and consent for any recording. A random collection of available mobile numbers is not automatically a representative national sample.
CAWI: when self-completed online surveys are credible
CAWI is attractive because responses flow directly into a dataset and participants can answer privately at a convenient time. However, digital access varies by age, resources, geography and user familiarity. The survey must be designed primarily for mobile screens where that reflects the audience, with simple navigation and response options. Verify the panel or invitation list, block duplicate participation where feasible and check unusual answer patterns without collecting unnecessary personal data. Findings should be described as applying to the recruited online population when broader coverage cannot be established.
Use the administrative research geography of Sierra Leone
A location frame in Sierra Leone should use the relevant geographic structures, such as districts, chiefdoms and local councils, rather than importing another country’s local government labels. The frame should distinguish where people live, work and access services from the administrative boundary used for supervision. A district or municipality may help organise field assignments without supplying a complete list of eligible respondents. Verify any boundaries and contact sources with field teams before sampling. These decisions affect who can enter the CAPI sample, which calling lists may be credible for CATI, and whether a CAWI panel covers the intended area.
Build a defensible sample before selecting devices
Sampling is not a technical appendix: it determines whether a result means anything outside the completed interviews. For CAPI, check area lists, selected dwellings or facilities and within-household respondent rules. For CATI, inspect how numbers were obtained and whether shared phones or invalid records change eligibility. For CAWI, document recruitment invitations, verification and self-selection. Allocate samples according to the inference required, not an identical quota copied from another project. A comparison of two selected cities remains a two-city result unless a broader probability frame is deliberately added.
Applying CAPI, CATI and CAWI in Freetown
In Freetown, the local research environment includes a coastal capital metropolitan area. A household livelihood or service-access survey might use mapped clusters and CAPI where the team must visit selected addresses, verify assets or record in-person observations. A CATI follow-up could be considered when respondents have willingly provided functioning numbers, while CAWI may suit a separately defined digitally reachable subgroup. These methods must not be substituted casually: each can select a different type of participant. Pilot questions and contact procedures within selected neighbourhoods before calculating the city estimate.
Applying CAPI, CATI and CAWI in Bo
In Bo, the team should independently assess who can be recruited and how, taking account of its character as an important southern commercial and educational centre. Check whether the listed households or users can be visited safely, whether sufficient valid numbers exist and whether online recruitment would exclude relevant communities. If a mode used in Freetown proves weak here, an adapted design may be justified, but preserve core indicator definitions. Note that two selected centres do not represent Sierra Leone as a whole; a claim about the entire country would require a wider sampling strategy.
Adapt questionnaire design for each survey mode
Mode selection affects how a question is understood. A CAPI interviewer may use a controlled showcard and verify that the correct person is answering. A CATI interviewer must read response options clearly without overwhelming the listener. A CAWI respondent needs concise instructions, mobile-friendly response controls and straightforward error feedback. Keep the underlying concept and reference period consistent while adapting presentation. Where identical wording is not feasible, test for mode effects. Do not merge apparently equivalent answers until the research team has assessed whether respondents interpreted them in comparable ways.
Test the actual languages respondents use
Interviewers and respondents may prefer different languages across the same city. Plan local screening, consent and questionnaire testing in Krio, English, Mende and other relevant languages, choosing versions based on the actual target group rather than a single presumed national language. CATI needs phrases that are easy to understand by voice and not overly long. CAWI needs instructions that remain clear without an interviewer. CAPI can support spoken clarification, but staff must not explain questions inconsistently. A short glossary, cognitive pilot and version-control register help maintain concept equivalence across languages and modes.
Plan access, travel and connectivity around local conditions
For this country, a practical design consideration is that chiefdom and city boundaries require different sampling procedures. Evaluate whether this affects road access for CAPI, call completion for CATI, or digital coverage and completion for CAWI. Conduct a reconnaissance and pilot in each selected centre. Estimate realistic interview duration, interviewer workloads, callback needs, connectivity and secure data transfer rather than applying an unchanged budget from another country. If teams change modes mid-project, document why and test whether the change affects the measured indicators.
Know when mixing modes improves coverage
A mixed-mode design can be sensible if the modes cover complementary groups by design. For example, CAPI might reach selected households lacking reliable numbers, while CATI covers an existing beneficiary list; CAWI might be reserved for digitally active professionals. Do not recruit convenient respondents from all three channels and call the total nationally representative. Agree how invitations will be tracked to prevent duplicates, which questions may be mode-sensitive, and whether final results will be shown separately or weighted into a defined combined population. The reasons for mode allocation should appear in the methods section before results are interpreted.
Apply mode-specific data quality checks
Quality assurance must match the risks of each mode. For CAPI, review interviewer movement, durations, route adherence, permissible GPS and back-check outcomes. For CATI, examine call dispositions, repeat-attempt patterns, script adherence and recordings only when lawful and consented to. For CAWI, check duplicate attempts, speeding, inconsistent identities and implausible response sequences. Apply predetermined thresholds fairly and investigate flags before excluding an interview. Digital evidence should be collected in proportion to the verification need and protected from unnecessary disclosure.
Treat consent and privacy as part of research design
Consent, privacy and safety cannot be delegated to the survey platform. A CAPI interviewer should explain the study in language the respondent understands, provide a private setting and collect only the identifiers necessary for the research. CATI requires sensitivity to who else can hear a call and whether the recipient is free to continue. CAWI needs a clear information screen, purposeful data collection and an easy way to stop. Recording, location tracking, contact-list use and data transfers should follow the rules and permissions applicable to the specific assignment.
Analyse mode effects and report coverage limits
Once data arrive, keep mode and recruitment information in the dataset. Examine completion patterns, item nonresponse and demographic composition separately for CAPI, CATI and CAWI. A mode difference may reflect sample composition, question presentation or both. Do not treat every difference as a finding about respondent attitudes. Use weights only where their derivation is credible and explain any residual coverage gaps. A transparent report tells readers how each group was reached, what estimates represent and where interpretation should remain cautious.
An illustrative survey decision for Sierra Leone
Imagine a research organisation assessing Sierra Leone residents’ experience of health or education services. One component may require direct observation of a facility, which favours CAPI; another may involve checking in with beneficiaries already enrolled on a verified contact list, which can favour CATI. A third component may solicit structured feedback from employees or registered online users, which may fit CAWI. The question is not which technology wins overall, but which population and evidence requirement each technology can legitimately serve. For Freetown and Bo, set different logistics assumptions while applying the same rules for respondent eligibility and data quality.
A method-selection decision for Sierra Leone should explicitly compare: population coverage; sample-frame defensibility; language and questionnaire fit; respondent privacy; requirements for direct observation; connectivity and travel constraints; consent and data protection; interviewer verification; nonresponse; and cost per valid, usable interview. A simple choice table can rank CAPI, CATI and CAWI against the particular study, rather than using a universal hierarchy. A cheap method that systematically misses core respondents is usually a poor value, while an expensive method with no extra evidence benefit may also be hard to justify.
What a credible survey report should contain
The study protocol should specify sampling units, city boundaries, contact or visit schedules, translated questionnaires, mode-specific recruitment procedures, quality checks, data storage and the rules for excluding or replacing cases. Reporting should provide separate denominator and nonresponse information for Freetown and Bo when they are compared, with a clear limitation on inference beyond those populations. Good survey research gives programme managers and business leaders evidence they can use, plus enough operational detail to understand its strengths and gaps. It does not disguise coverage problems behind a high response count.
How Surveysphere Africa can support
Surveysphere Africa supports the design and delivery of CAPI, CATI, CAWI and carefully planned mixed-mode studies. For projects in Sierra Leone, including Freetown and Bo, the team can help define a credible sample, localise instruments, supervise fieldwork, verify data quality and explain which populations the evidence represents. The best method is the one that reaches the intended respondents and yields defensible decisions.
Related guidance
For the continent-wide view, read our guide to CAPI, CATI and CAWI.
Our services for research in Sierra Leone
We run research across African markets. Start with these services for work in Sierra Leone:
- Outsourced fieldwork in Sierra Leone: CAPI, CATI and CAWI data collection with live quality control.
- Market and consumer research in Sierra Leone: Market-entry, consumer and retail research.
We also offer: Monitoring, evaluation and learning, Social and development research, Public health research, Policy, economic and institutional research, Data analytics and insights visualisation.
