In-Home Use Test: How Many Households to Recruit in India

Recruit the usable households you need divided by the completion rate you expect, rounded up. A usable household is one that completes every required step. The multiplier is 1 ÷ completion rate: 1.11 at 90%, 1.18 at 85% and 1.54 at 65%.

The three completion rates below are our planning assumptions, not measured completion rates. We use 90% as a good case, 85% as a typical case and 65% as a cautious case. This is our model, not an official figure.

Recruit = target ÷ completion rate, rounded up.

For example, 60 ÷ 0.65 = 92.3, which rounds up to 93.

Worked example. You are testing a new hair oil against the current one and want 40 usable households per product.

• At 85% completion you recruit 48 per product (40 ÷ 0.85 = 47.06), which is 96 households.
• At 65% completion you recruit 62 per product (40 ÷ 0.65 = 61.54), which is 124 households.
• Budget for the second number unless your fieldwork partner can show a completion record for the same kind of household and product. A fieldwork partner is the agency or panel that recruits households and runs the study on the ground.

Apply the sum to every group you want to read separately. If you need 30 usable households in each of three cities, calculate the recruit for each city, because a shortfall in one city cannot be topped up from another.

What target should you choose? These are our recommendations, not a statistical rule:

• 10 to 20 households: a pilot to test the instructions and logistics.
• 15 to 30 per audience: a diary study, in which participants log their use over days. It finds patterns and language. Sample size in qualitative research explains how to judge when you have heard enough.
• 30 to 99 per product: a directional read, meaning an indication of which variant leads, not a precise margin.
• 100 or more per product: a comparison between variants, but only for large gaps.

Here is the working behind that last line, and it is our calculation. For two products, the standard two-proportion formula is n per product = (z for 5% significance, two-sided + z for 80% power)² × [p1(1 − p1) + p2(1 − p2)] ÷ (p1 − p2)². Here z is 1.96 for 5% significance and 0.84 for 80% power, so the first term is (1.96 + 0.84)² = 7.84. Power is the chance of detecting a real gap. Take the share choosing the top two answers on a rating scale (top-two-box):

• 50% versus 70%, a 20-point gap: 7.84 × (0.25 + 0.21) ÷ 0.04 = 90.2, so 91 per product.
• 50% versus 60%, a 10-point gap: 7.84 × (0.25 + 0.24) ÷ 0.01 = 384.2, so 385 per product.

The calculation ignores clustering and weighting. It is usable for planning. Work backwards from the smallest gap that would change your decision, and if it is small you need the larger sample.

Households drop out at delivery, first use, unclear instructions, the middle of the study and unclear rewards. Each can be checked early, which costs far less than recruiting extra households at the end.

• Delivery. Ask every household to confirm receipt. We recommend replacing any household that has not confirmed within three days of dispatch, while the recruiting pool is still available.
• First use. In our experience (not a measured statistic), households that have not used the product within 48 hours of delivery rarely start. We recommend one reminder, then a replacement.
• Instructions. Test the leaflet and the questions with three to five households before the main wave, which is one round of fieldwork. Run them in the language participants will use. If anyone needs a phone call to start, rewrite the leaflet.
• The middle of the study. Keep daily check-ins to a minute or two and save the longer assessments for the middle and the end. Ask for a dated photo or short video at least once, because it is proof of use.
• Rewards. Tell households what they receive and when before they agree. We communicate the reward to participants before they take part, and we process incentives after completion has been validated.

For long-running tasks, Nielsen Norman Group's guide to diary studies is a useful companion.

Choose an IHUT when the answer you need appears only after several uses or only makes sense at home. Choose a central location test (CLT), where participants come to one venue and test products under controlled conditions, when you need an immediate reaction under identical conditions.

Our recommendation is to pair methods. Use a CLT to remove weak variants cheaply, then put the survivors into an IHUT.

Run the test for as long as the product's natural use cycle needs, and no longer. A single-serve drink needs one use occasion. A cleaning product needs several uses across a week. A skincare or haircare claim usually needs about two weeks to show a visible effect. This is our recommendation, and the real use cycle of your product should override it.

A usage period longer than the product needs adds burden for participants and, we expect, dropout. Plan the whole project, including recruitment, dispatch and reporting, for several weeks and not just the usage period.

Before shipping, you need a named decision, a written usage period, a recruit number above target, a factual screener, tested instructions, confirmed delivery, proof of use, restricted address handling, a safety contact, unit reconciliation and a stated incentive. A screener is the set of qualifying questions that decides who can join. Each item below is a test you can run on your own plan.

For products people eat or put on skin, ask your regulatory or legal team to approve sampling of unreleased formulations before dispatch. That sign-off is a decision for your own advisers.

An IHUT collects names, addresses and phone numbers, which are personal data under the Digital Personal Data Protection Act, 2023 (DPDP Act). The Government of India notified the Digital Personal Data Protection Rules, 2025 in November 2025. As of October 2026, most notice, consent and data-fiduciary duties are not yet in force. A data fiduciary is the organisation that decides why and how personal data is processed. The consent-manager provisions start on 13 November 2026, and most remaining duties start on 13 May 2027, 18 months after the Rules were published.

We recommend building consent and deletion into your IHUT now:

• Collect consent that names the purpose, who will see the address and when it will be deleted. Our guide to informed consent in research and the Indian rules walks through it.
• Recruit adults only.
• Give the brand anonymised participant IDs, not the address sheet.
• Follow the participant protections in the code of ESOMAR (the global research association) and the ICC (International Chamber of Commerce): the ICC/ESOMAR International Code.

We recruit and screen the households, coordinate them through the study and process their incentives. Qualfacto is a qualitative research participant panel in India, and Product Testing (IHUT) is one of the study formats on our panel, listed as Product + Cash Reward.

You share a brief covering the research objective, target audience, geography, sample size and timelines. We assess feasibility and send a tailored proposal and quote. Once scope, commercials and timelines are agreed, recruitment begins. After completion and validation, we process participant incentives, and you receive the agreed deliverables.

• Reach. Our recruitment covers major metros, Tier 1 and Tier 2 markets, and urban, semi-urban and rural locations. Language needs are assessed study by study.
• Pilot. We are open to a small pilot or introductory first project, so you can judge participant quality and execution before a larger study.
• Cost. We price each project individually, depending on methodology, audience, sample, geography and recruitment difficulty, so there is no fixed rate card. The user research recruitment cost worksheet for India sets out the cost drivers.