2024 is a huge year for elections, with more than 60 countries holding national elections and over half the world’s population voting. With each election it can seem like opinion polls dominate the coverage but how are these polls carried out? We speak to pollster and data analyst David Byler from the American non-partisan polling company Noble Predictive Insights about how it all works.

We also hear from the BBC’s North America correspondent Anthony Zurcher, who explains how significant the polls are in the 2024 US Presidential election between Kamala Harris and Donald Trump.

Historically there have been lots of poll prediction fails. BBC journalist Rupsha Mukherjee in Delhi tells us about how some important polls got it wrong in India’s general election this year. And Niko Kelbakiani, a journalist at BBC Monitoring, explains the role opinion polls play in Iran’s elections - where the Guardian Council must approve every candidate.

Instagram: @bbcwhatintheworld WhatsApp: +44 0330 12 33 22 6 Email: whatintheworld@bbc.co.uk Presenter: William Lee Adams Producers: Julia Ross-Roy, Benita Barden and Hayley Clarke Editor: Verity Wilde