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Christopher Charles | Explaining misinterpretation of public opinion polls

Published:Sunday | September 24, 2023 | 12:06 AM
In this September 2020 photo, supporters of PNP and JLP pose for a photo at Constant Spring Primary and Junior High School.
In this September 2020 photo, supporters of PNP and JLP pose for a photo at Constant Spring Primary and Junior High School.
Christopher Charles
Christopher Charles

Many critical thinkers find the misinterpretation of poll findings abhorrent. This misinterpretation has been occurring for many years. The problem is perpetrated by some pollsters, some political commentators, and some journalists who are the gatekeepers of the information reaching the public.

One problem that bedevils them, which is the focus of this column, is the misinterpretation of polls showing a statistical dead heat. There are other problems that will be discussed in a future column. Public opinion polling, particularly pre-election polls, are well established and globally accepted predictive polls that are mostly correct when the scientific method is followed.

The interpretation of two recent pre-election polls highlight the problem. The People’s National Party (PNP) commissioned June 2023 Don Anderson Poll reported that the PNP had 35 per cent support, and the Jamaica Labour Party (JLP) 30 per cent with a margin of error of plus three per cent or minus three per cent. Polls should not be interpreted without considering the margin of error, the extent to which the polls may be wrong. The PNP with plus three per cent could be eight per cent ahead, the lead of five per cent added to the plus three per cent margin of error, or the PNP could be two per cent ahead, take the minus three per cent from the five per cent lead. It is best to stick with the slim two per cent lead for the PNP since part of its small five per cent lead falls within the margin of error. The PNP has a negligible lead of two per cent.

The August to September 2023 Blue Dot-Nationwide Poll reported that the JLP had 31 per cent support and the PNP 25 per cent with a margin of error of plus 2.75 per cent, or minus 2.75 per cent, which I round off to three per cent. The JLP could be nine per cent ahead, the plus three per cent margin of error added to the six per cent lead, or three per cent ahead, the minus three per cent margin of error out of the six per cent lead. I will stay with the slim three per cent lead for the same reason given above for the PNP.

The JLP and the PNP are in a statistical dead heat which means they are tied in the party standings. The Blue Dot-Nationwide Poll (three per cent JLP lead) and the Don Anderson Poll (two per cent PNP lead) are saying the same thing. A one percentage point difference in popularity is meaningless. Large sections of the public that argued that the PNP was leading in June is now saying that the JLP is leading.

The question to be asked is why some journalists, some political commentators and some pollsters are inaccurately interpreting the polls showing a statistical dead heat thereby misleading the public. Two easy explanations that readily comes to mind are innumeracy because of poor Caribbean Secondary Education Council mathematics passes over many years, and the lack of integrity in the country. We should not ignore these reasons the but there are other potent interconnected reasons for the misinterpretation problem. I explain some of these reasons.


The idea pathogen of postmodernism is embedded in the minds of some gatekeepers. Postmodernism’s main argument is that here are no universal truths except the assumption that there are no universal truths. Therefore, gatekeepers pick a winner when some or all the difference between the parties fall within the margin of error. They look at the same poll numbers and arrive at “their truth”.

How they feel about the issue is more important than what is true. They feel it is their right to interpret the scientific evidence as they wish. Despite its popularity, postmodernism is anathema to the scientific method, and has obliterated critical thinking among certain sections of the academy and so is a danger to human progress. Some postmodern “scholars” will be upset but I stand with the scientific method that determines what is true through objective measurement.


People do not like ambiguity when they have to interpret things. Intolerable uncertainty makes people psychologically uncomfortable so they want a clear-cut leader or winner declared in the polls. People demand that pollsters “call it”. Any pollster who cannot call it is not worth her or his salt. The parties are in a political race and they both cannot share the gold medal. There cannot be two leaders in the same poll, or two winning parties in the same electoral race.

This situation pressures some pollsters to engage in misinterpretation. I have seen pollsters initially explained statistical dead heat results and subsequently declared a leader saying that the momentum is with party A without conducting a new poll. There is no way these pollsters could detect party A moving ahead of party B without going back into the field.


Some media houses and journalists are caught up in the public’s demand to know the leader or winner. This demand also shapes how some journalists interpret the polls reinforced by the time-honoured code among some journalists that sensationalism sells. These headlines attract readers and listeners. Increasing readership and listeners creates a larger market and increase earnings from advertisements in a situation where some media houses in Jamaica are struggling financially.

There is also the influence of unconscious partisan bias (some will say deliberate bias), where some of these gatekeepers structure their interpretations of the polls in support of their political party without realising this. We all suffer from cognitive traps that negatively influences our decision-making.


Traditional media prides itself on taking a balanced approach to issues by allowing multiple viewpoints from political commentators with limited expertise. Common sense is elevated over scientific evidence in these discussions and political scientists are seldom invited to be a part of the discussion. What is worse is that I have never seen a statistician invited to be a part of the discussion. A related problem is that some pollsters are insufficiently assertive.

Although these pollsters state the importance of the margin of error, they allow some political commentators and some journalists to take the discussion south of the evidence. It was in similar discussions of the past that the late pollster Professor Carl Stone was deemed arrogant and aggressive because he did not allow people without the expertise and skills to dominate the narrative about his poll results.


Some people become suspicious and distrustful when an insignificant lead is explained away within the margin of error because of declining trust among Jamaicans. Trust is the psychological glue that holds people, leaders and institutions together in society. Moreover, with many competing and varied sources of political information in the digital age, these distrustful citizens latch on to these contradictory sources of information. These Jamaicans refuse to believe in a science that is unable to declare a leader, or winner, like how they refuse to believe in a science that cannot make a vaccine which provides 100 per cent immunity.

The interpretation problem creates public confusion and undermines the credibility of polls. Therefore, the media should invite a statistician and a political scientist on discussion panels to help with interpretation, guests should be mindful of their biases, pollsters should be conversant with the science of voting behaviour, and how the Westminster and the first-pass-the-post systems work to contextualise the interpretation of pre-election polls. Finally, some political commentators and journalists should brush up on their basic statistics, and the latter should push evidence rather than perspectives to enlighten the public.

Christopher Charles, PhD, is a professor of political and social psychology in the Department of Government at the University of the West Indies, Mona. Send feedback to