ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS All ESOMAR world research codes and guidelines, including latest updates, are available online at www.esomar.org © 2009 ESOMAR/WAPOR. All rights reserved. No part of this publication may be reproduced or copied in any form or by any means, or translated, without the prior permission in writing of ESOMAR or WAPOR. The ESOMAR/WAPOR Guide to Opinion Polls and Published Surveys was drafted in English and the English text is the definitive version. ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS CONTENTS Introduction to the guide 2 1. Opinion polls and democracy – an overview 3 q q A A f 2. frequently asked questions about polls 4 f 3. Guideline for the publication of opinion poll and survey results 14 3.1 Introduction 14 3.2 Scope 16 3.3 Requirements of the ICC/ESOMAR International Code 16 3.3.1 General requirements 16 3.3.2 Specific requirements for published researchers commissioners public opinion surveys 17 OR f 3.3.3 Arrangements between the Research AND Organisation and its Client 21 4. Specific guidance on conducting pre-election opinion polls and polls on voting intention 24 4.1 Introduction 24 4.2 The Guidelines 25 4.2.1 Timing of fieldwork 25 4.2.2 Sample size 25 4.2.3 Sample distribution 26 4.2.4 Telephone interviewing 27 4.2.5 Online polls 27 4.2.6 Weighting 28 4.2.7 Adjustments 28 4.2.8 Survey content 29 researchers 4.2.9 Time series 29 OR 4.2.10 Consistent design 29 f 4.2.11 Indicator variables 29 4.2.12 Unusual poll results 30 5. Guideline on conducting exit polls and election result forecasts 31 5.1. Introduction 31 5.2. Specific requirements for exit polls 31 5.2.1. Items for minimal disclosure 32 5.2.2. Election projection methods and their disclosure 34 ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS Introduction to THE GUIDE and published according to the ESOMAR Guideline for the Publica- Public opinion polls are regularly con- tion of Opinion Poll Results. The ICC/ ducted and published in many coun- ESOMAR International Code and this tries. They measure not only support associated Guideline are observed by for political parties and candidates, but members of ESOMAR working in more also public opinion on a wide range than 100 countries around the world. of social and political issues. They are published frequently by a variety of Second there is a section on frequently print, online and broadcast media. asked questions about how to judge the quality of an opinion poll. These The public discussion of opinion polls questions are designed to help journal- is not always well informed. However, ists, politicians, academics, the public the case for restricting the publication and other interested parties understand of polls during election campaigns is how to judge the quality of an opinion hard to support with rational argument poll. or empirical evidence. ESOMAR and WAPOR have produced the present Third there is the ESOMAR Guideline guide in order to help those interested for the Publication of Opinion Poll and in the subject of opinion polls to reach Survey Results which is intended to a more informed judgement about reduce the risk of the public being the value of such polls and the most misled by research which is inadequate appropriate ways of conducting and or badly presented or interpreted. reporting them. fourth there is a section which pro- There are five sections in this guide. vides specific guidance for practitioners on the conduct of pre-election polls. first there is a statement on the role of opinion polls in democratic systems. finally, there is a Guideline for the ESOMAR and WAPOR’s position on Conduct of Exit Polls and Election Re- this issue is quite clear. We believe that sults Forecasts. These last two guide- there should be no restriction on the lines are designed to help ensure that conduct or publication of opinion polls election polls are carried out to high which have been carried out according standards.They provide technical guid- to the ICC/ESOMAR International ance to researchers and background Code on Market and Social Research information but they are not intended to ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS WHy opinIOn pollS ARE essenTIAl FOR democracy 3 be a “How to do it” manual. The subject of the results of opinion polls tell read- of public opinion research and the ers and listeners that their opinions are measurement of voting intention con- important, and can even sometimes be tinue to evolve and each election may more important than the opinions of the bring new circumstances the research- elite. er must address. The professional skills and previous experience of polling The democratic urge towards participa- organisations are essential components tion and the journalistic desire to ask of effective public opinion research. It is questions have merged to create the not possible to write them into guide- extensive media polling of the last 70 lines or codes of practice. years. Imagine a political system where the public is told what it thinks by its 1. OPINION polls AND political leaders, where election win- democracy – AN overview ners have the ability to tell voters why they voted the way they did and where Public opinion is a critical force in the government, when it looks for pub- shaping and transforming society. lic input, asks only its friends what Properly conducted and disseminated the public thinks. The alternative to survey research gives the general properly conducted polls is a public and public an opportunity for its voice to be a government exposed only to unscien- heard. Through opinion research the tific and probably inaccurate assertions public, politicians, the media and other about what people believe, in many interested groups have access to cases presented by partisan individuals accurate measures of public attitudes or organisations with a political agenda. and intentions. “Scientific” polling is among the most successful political developments of the last century. Public opinion polls help guide policy by giving decision-makers impartial information about what the public wants. Polls also alert the public to their own hopes, desires, and politi- cal goals. They are mirrors, permitting individuals to understand where they fit into the political system. Media reports ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS 4 UnderstandInG opinIOn pollS 2. fREquently ASkED Internet polls); or visits randomly- questions ABOUT polls drawn addresses or names from a list such as an electoral register (for some 1. What is an opinion poll? face-to-face surveys). The polling An opinion poll is a scientific and repre- organisation then contacts people on sentative survey designed to measure those telephone numbers or at those the views of a specific group – for addresses, using a random selec- example a country’s electors (for most tion procedure, and asks them to take political polls) or parents or trade union part in the survey. “Quota” sampling members. involves setting quota controls – for ex- ample, age and gender – and letting the 2. What makes a survey “scientific”? interviewer seek out different people The two main characteristics of sci- who, together, match those char- entific surveys are a) that respondents acteristics. Surveys based on quota are chosen by the research organisa- sampling are often used in face-to-face tion according to explicit criteria to surveys. In addition, some Internet polls ensure representativeness, rather than employ quota sampling to select repre- being self-selected, and b) that ques- sentative samples from a database of tions are worded in a balanced way. people who have already provided such For example, if the population being information about themselves. Quota sampled contains 52% who are women sampling may be used, in otherwise and 30% who are over 55, then a sci- randomly sampled telephone surveys, entific opinion poll will represent those to select the person to be interviewed groups appropriately and the ques- within the household, in order to speed tions will be balanced and not lead the up the fieldwork process. respondent towards a particular answer. 4. Do polling companies do anything else to achieve representative 3. How does a poll choose a sample samples? that is truly representative? yes, they do. While well-conducted There are two main methods. The first random and quota samples provide is “random” sampling, the second “quo- a broad approximation to the public, ta sampling”. With random sampling, a there are several reasons why they polling organisation either uses a list of might contain slightly too many of some randomly-drawn telephone numbers or groups and slightly too few of others. email addresses (for telephone or some What normally happens is that polling ESOMAR WORLD RESEARCH CODES & GUIDELINES ESOMAR/WAPOR GUIDE TO OPINION POLLS AND PUBLISHED SURVEYS UnderstandInG opinIOn pollS 5 q A f companies ask respondents not only the kind of extra information (such as about their views but also about them- gender and age) that would allow some selves. This information is then used to judgement to be made about the nature compare the sample with, for example, of the sample. census statistics. The raw numbers from the poll may then be adjusted 6.