Methodology · 4 min read

CATI Telephone Surveys Sample Size and Sampling Guide for India

How to choose the right sample size and sampling approach for cati telephone surveys in India, including quotas, city splits and segment reads.

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Quick answer

The right sample for cati telephone surveys depends on how many segments you need to read separately and how precise each reading must be. In India, also plan quotas by city tier, region, age, gender and socio-economic class (NCCS).

At a glance

Guide type: Methodology · 4 minute read
Method covered: CATI Telephone Surveys
Research family: Quantitative research
Typical timeline: 2–4 weeks end to end, which makes it the fastest route to a representative read
Typical sample: 300–800 completes; budget eight to twelve dials for every completed interview
Written for: Analysts sizing the sample · Data leads reviewing a design · Anyone asked “is this enough?”

Key takeaways

Plan sample per segment, not just in total
Use NCCS for socio-economic quotas in India
Weight results to match the population
Qualitative samples are about saturation, not statistics

Reader intent

Who this guide is for

Three readers arrive here with different problems. Each should be able to act on this page without reading all of it.

Analysts sizing the sample
How to get from a decision to a defensible cati telephone surveys sample, rather than to a round number.
Data leads reviewing a design
Frames, quotas, weighting, and the bases you can and cannot report on.
Anyone asked “is this enough?”
The answer depends on the precision the decision needs. This guide shows how to work that out.

Start with segments

Decide which groups you must compare, for example metro versus Tier 2, or users versus non-users. Each needs a robust base.

Quotas that matter in India

City tier and region
NCCS socio-economic classification
Age and gender
Category usage
Language

Statistical precision

Larger samples narrow the margin of error, but the gains shrink as samples grow. Balance precision against cost per segment.

How Market Research India can help

Market Research India designs and runs cati telephone surveys projects across 50 Indian cities and 30 industries. A senior research director leads every study, and our own supervised teams handle the fieldwork. You get clear recommendations, not just data tables.

Share your objective and we will send a scoped, fixed-fee proposal within 24 hours, with a recommended method, sample and timeline.

What goes wrong

Common mistakes in cati telephone surveys

Most disappointing cati telephone surveys studies fail for reasons that were visible in the design, not in the fieldwork. These are the ones we see most often, and what to do instead.

01
Calling only during office hours
A sample collected between 11am and 5pm over-represents people who are not at work. Spread dials across three time slots and include weekends.
02
Dialling a stale list
An unchecked database burns the budget on dead numbers before it reaches a respondent. Clean, dedupe and test-dial a sub-sample first.
03
A script written for the eye, not the ear
Long scales and nested brackets work on paper and collapse on a phone call. Read every question aloud before it is programmed.
04
Monitoring too few calls
Without live listening on at least 10% of calls you cannot tell a refusal conversion from a leading prompt. Audio-audit a further sample afterwards.
05
Significance claimed on thin bases
A gap between two sub-groups of forty respondents is rarely real. Agree the minimum reportable base before field and grey out everything below it in the tables.
06
A questionnaire nobody piloted
Routing errors, ambiguous scales and a 35-minute runtime are cheap to find in a 30-interview pilot and expensive to find in the full dataset.

Run through this before sign-off

Your checklist before you brief anyone

A working sequence for a cati telephone surveys project. Most of it costs nothing, and it saves the two weeks a re-field would take.

1
Clean, dedupe and screen the number list against do-not-call registers before dialling begins.
2
Keep the interview under 12 minutes and read the script aloud before programming it.
3
Train interviewers on refusal conversion, with a scripted response to the three common objections.
4
Spread dials across morning, evening and weekend slots, with at least four attempts per number.
5
Live-monitor 10% of calls and audio-audit a further 10% with supervisor notes attached.
6
Agree the minimum reportable base before fieldwork, and hold the line in the tables.
7
Agree in writing who acts on each finding, and by when, before the debrief ends.

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Answers

Frequently asked questions

The questions buyers ask us most often before they commission cati telephone surveys.

What is NCCS?

The New Consumer Classification System, India's standard socio-economic classification based on education and household durables.

From guide to project

Where cati telephone surveys actually gets commissioned

If this guide has settled the method, these are the pages worth opening next: the service itself, and the markets where cati telephone surveys is most often run for our clients.

Keep exploring

CATI Telephone Surveys Sample Size and Sampling Guide for India

Who this guide is for

Start with segments

Quotas that matter in India

Statistical precision

How Market Research India can help

Common mistakes in cati telephone surveys

Your checklist before you brief anyone

Frequently asked questions

Where cati telephone surveys actually gets commissioned

More reading on cati telephone surveys

More on cati telephone surveys

Other methodology articles

CATI Telephone Surveys city by city

Related research services

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