Skip to comments.Likely Voters VIII: (Guide to Each Pollsters' Definition of Likely Voter; They're not the same)
Posted on 09/13/2012 6:25:55 AM PDT by xzins
ABC conducts surveys jointly with the Washington Post, but each organization applies its own weighting and likely voter models (the Washington Post's procedures are described separately, as the end of this page).
Mechanics - The ABC methodology page explains their likely voter models:
Our practice at ABC News is develop a range of "likely voter" models, employing elements such as self-reported voter registration, intention to vote, attention to the race, past voting, age, respondents' knowledge of their polling places and political party identification. We evaluate the level of voter turnout produced by these models and diagnose differences across models when they occur."
In an email, Polling Director Gary Langer said that ABC uses "straight cutoff models," which they use the variables above in some way, presumably an index, to rank voters by their likelihood to vote and select those at a certain "cutoff level." He also said that "turnout ranges across models" although he did not elaborate.
New registrants - Langer said that registrants could qualify as likely voters, but again, he did not elaborate. An ABC survey release on October 19 said that 10% of their likely voters say 2004 will be the first time they vote in a presidential election.
Party ID - Starting in early October, the ABC pre-election tracking did incorporate weighting by party identification into their model as described thusly on their methodology page:
Keeping in mind that actual change can occur, but also that random movement can distort, our solution is to compute an average of party ID as measured in our nightly tracking poll, and party ID as measured in recent presidential elections. This averaging approach allows us to pick up real movement in party ID while constraining random variability
Methodology links - ABC has a five-page methodology disclosure, a guide to public opinion and primer on response rates
Mechanics - Likely voters are self-described registered voters who say they have a great deal or quite a bit of interest in following news about the campaign (Q.LV3 - text below) AND one of the following:
- Voted in 2000 (Q.LV1) AND rating of 8-10 (Q.LV2), OR;
- Did not vote in 2000 because too young to vote (Q.LV1) AND rating of 8-10 (Q.LV2), OR;
- Did not vote in 2000 for reason other than too young AND rating of 10 (Q.LV2).
Likely voters were 75% of registered voters or 61% of all adults on their Oct 22-26 survey
1. Are you currently registered to vote at this address, or not?
LV1. Sometimes things come up and people are not able to vote. In the 2000 election for President, did you happen to vote? (IF NO, ASK:) Why not?
LV2. On November 2nd, the election for President will be held. Using a 1-to-10 scale, where 10 means you are completely certain you will vote and 1 means you are completely certain you will NOT vote, how likely are you to vote in the upcoming presidential election? You can use any number between 1 and 10, to indicate how strongly you feel about your likelihood to
LV3. How much interest do you have in following news about the campaign for President, a great deal, quite a bit, only some, very little, or no interest at all?
Party ID - AP-IPSOS does not weight by party ID.
The American Research Group (ARG)
Mechanics - ARG uses three direct questions to determine likely voters: (1) a 1 to 10 scale (definitely not vote to definitely vote) for self-assessment, (2) a question on interest in the election (not interested at all, not too interested, somewhat interested, very interested), and (3) past voting behavior (always vote, vote in most, vote in at least half, vote in less than half, never vote/have never voted), plus sex and age.
An email from ARG President Dick Bennett adds the following:
Past research using samples with voter histories appended to the files shows that 9's or 10's in the self-assessment scale do vote and are therefore likely voters. The real problem is with the 7's and 8's. Our software constructs a discriminant model from a sample of the 9's and 10's and then applies it to the remaining 7's, 8's, 9's, and 10's. An average of the probabilities of the 9's and 10's is created and if the 7's and 8's match or exceed the average probability, they are considered likely voters. This may sound complicated, but the software does it automatically. We also can bounce any 9's and 10's that don't fit the population of likely voters.
(I have a tendency to increase the average probability generated by the model. It becomes a problem when the 7's and 8's differ from the 9's and 10's in ballot preference. Most times, however, the 7's and 8's do not differ in ballot preference. When they do and I have ignored the model, I note it in the results.)
Our latest surveys are showing about 85% of registered voters coming through as likely voters. That is not going to happen, but we do know that a likely voter does not need to actually vote on election day to represent voters on election day. Random events will prevent some likely voters from voting on election day and a 7 or 8 does not have any greater chance of being prevented from voting than a 9 or a 10.
New registrants can be classified as a likely voter and it is also possible for someone stating that they intend to register on election day but are not registered when we talk to them. The whole purpose of the discriminant model is to include voters who give 7's and 8's if it looks like they will vote. A new voter's 7 or 8 may be equivilent to the 10 of a voter who always votes.
Party ID - ARG does not weight by party ID.
The Battleground survey is conducted by two campaign polling firms, The Tarrance Group (R) and Lake, Snell, Perry (D).
Mechanics - The Battleground survey selects likely voters by screening for voters who say they are registered to vote and are at least somewhat likely to vote (see text below). They also screen out anyone employed by an advertising agency, newspaper, or television station. They do not set a specific cut-off percentage.
Question text -
A. Are you registered to vote in this state?
B. Now, thinking ahead to the elections that will be held this November -- What is the likelihood of your voting in this upcoming election -- are you extremely likely, very likely,
somewhat likely, or not very likely at all to vote?
C. Are you, or is anyone in your household, employed with an advertising agency, newspaper, television station?
New Registrants - can qualify as long as they say they are at least somewhat likely to vote.
Regional stratification - The survey sets pre-interviews quotas by state and by gender. These quotas are set using statistics for registration and past turnout. They determine the percentage contribution of each state to the total number of registered voters and past voters, then create an average that "uses one part registration and two parts turnout."
Party ID - The Battleground Survey weights party identification to GOP=42.3%, Independent=15.4%, Democrat=42.3% (Their percentages for Democrats and Republicans include independents who lean to one of the parties on a follow-up question). In an email, the Tarrance Group explained that their party targets were arrived at "in collaboration with Lake, Snell, Perry to weight the data in the most fair and accurate manner possible."
CBS News/New York Times
Mechanics - CBS News uses a unique procedure that weights each registered voter by their likelihood of voting. This procedure uses the responses of ever registered voter in the sample, only at different weighted values. CBS describes their likely voter model in great detail here. I described it in this post.
New Registrants - are included, although their answers are presumably weighted lower than other respondents, since new registrants typically turn out to vote at lower levels.
Party ID - CBS News does not weight by party ID.
Methodology Page- CBS has a methodology page and a seperate description of how they select likely voters. he New York Times always includes a lengthy methodology description with each poll.
Democracy Corps - conducted by Democratic pollster Greenberg Quinlan Rosner Research
Mechanics - Select likely voters with screen questions. A likely voter is a registered voter who voted in either the 2000 Presidential or 2002 Congressional election and reporters they are at least "probably" going to vote next year (see question text below). They drop the past turnout requirement for those not young enough to vote in 2000 or who otherwise registered since 2000
Question text -
Q.3 First of all, are you registered to vote at this address?
Q.4 Many people weren't able to vote in the 2000 election for President between George Bush, Al Gore, and Ralph Nader. How about you? Were you able to vote, or for some reason were you unable to vote?
Q.5 Were you registered to vote at that time and did not vote, or were you not registered to vote?
Q.6 As you know, there was an election for Congress and other offices in 2002. Many people weren't able to vote. How about you? Were you able to vote or for some reason were you unable to vote?
Q.7 Were you registered to vote at that time and did not vote, or were you not registered to vote?
Q.8 What are the chances of your voting in the election for President this year: are you almost certain to vote, will you probably vote, are the chances 50-50, or don't you think you will vote?
New Registrants - New registrants can classify as likely voters as long report they will probably or definitely vote (on Q8 above).
Regional stratification - Democracy Corps sets regional quotas based on past vote and registration statistics.
Party ID - Democracy Corps does not weight by party ID.
Fox News/Opinion Dynamics
Mechanics - Each respondent is screened to establish him/her as a registered voter who voted in the 2000 presidential election or has registered since then. In states without registration or same-day registration, the question asks about the frequency with which the individual votes. The likely voter scale scores respondents through a series of additional questions about past voting behavior and interest in voting in the current election."
New registrants - a person who has never registered before has to show very high levels of interest and intention to make it into the survey anyway.
Regional stratification -Fox News/Opinion Dynamics regionally stratifies its random digit dial (RDD) samples by past turnout statistics so that numbers from across the country are selected in proportion to the number of voters in each state.
Party ID - The Fox News/Opinion Dynamics survey does not weight by party ID.
Methodology page - http://www.foxnews.com/story/0,2933,95854,00.html
*Mechanics - I have described the Gallup model at length beginning with this post. Gallup creates a seven point index based on answers to seven questions as shown below. Under 21 respondents can receive up to 3 bonus points depending on their answers to other questions. Likely voters are typically sevens, plus sixes weighted down to a cutoff percentage. Gallup had been setting the weighted cutoff to 55% of its adult samples. Jeff Jones of Gallup reported that the cutoff would be increased to 60% for its last survey.
1) How much have you thought about the upcoming elections for president, quite a lot or only a little? (Quite a lot = 1 point) 2) Do you happen to know where people who live in your neighborhood go to vote? (Yes = 1 point)
3) Have you ever voted in your precinct or election district? (Yes = 1 point)
4) How often would you say you vote, always, nearly always, part of the time or seldom (Always or nearly always = 1 point)
5) Do you plan to vote in the presidential election this November? (Yes = 1 point)
6) In the last presidential election, did you vote for Al Gore or George Bush, or did things come up to keep you from voting?" (Voted = 1 point)
7) If "1" represents someone who will definitely not vote and "10" represents someone who definitely will vote, where on this scale would you place yourself? (Currently 7-10 = 1, according to this "quiz" on USA Today)
New Registrants - 18-21 year olds get bonus points. On a survey in late October, 6% of likely voters said they will cast their first presidential vote in the 2004 election. See this post for more details.
Party ID - Gallup does not weight by party ID.
Methodology page - While Gallup does not have a methology page per se, Gallup often answer methodological questions on their Editor's Blog.
Mechanics - Harris screens for likely voters using questions on registration, likelihood of voting, past voting, whether the election might make a difference and interest in election.
According to an email Harris' David Krane, they do not use a specific cut-off percentage, though likely voters as a percentage of the adult sample "ranges anywhere from 65%-80% depending on the set of questions that we use."
New Registrants - Harris identifies new registrants as part of their registration question. Without elaborating, the email from Harris states that new registrants can qualify as likely voters.
Party ID - Harris does not weight by party ID, but Krane added, "We really would prefer not to weight by party - we strongly feel this way - but we haven't ruled it out. If there are really weird skews from previous surveys and previous years we might consider it but it would really have to be a last resort."
International Communications Research (ICR)
Mechanics - The ICR selects registered voters with a screen that consists of registered voters who say they are "absolutely certain" they will vote. The certainty question, similar to ones others use, has the following response options: absolutely certain, probably, or 50-50 or less. Via email, David Dutwin of ICR reports: "We find that around 86-88% of registered voters say they are absolutely certain."
New Registrants - Since the screen does not include past voting, new registrants can qualify if they are absolutely certain to vote.
Party ID - ICR does not weight by party ID, but Dutwin ads via email, "we do not have a hard and fast rule about this...we have yet to be more than 2% off on the [average] Democrat and Republican numbers, and once we were 4% off with independent."
Mechanics - Insider Advantage the only survey organization on this listing that uses lists of registered voers to draw all samples. While several national media polls (including ABC/Washington Post and Quinnipiac) experimented with list based samples, all continue to draw samples during the current election season using the random digit dial (RDD) methodology.