Image caption Grace Marner says political quizzes are a simpler way to understand politics

Confused about how to vote? Overwhelmed by political jargon? A number of online political quizzes claim they can help.

The idea is simple - you answer some questions about your policy preferences, then an algorithm spits out a party recommendation.

"It's so difficult to take in and understand everything you read about the election and the manifestos, these quizzes seem a simpler way to understand politics and what party your views are most similar to," says Grace Marner, a 21-year-old student in Hull.

The quizzes come in a variety of formats. On the site ISideWith, people are asked lots of questions like "Should the UK abolish university tuition fees?" They can say yes, no, or choose more nuanced responses like "Yes, but only for UK citizens". They can also indicate which issues are most important to them.

GE2017, currently in beta mode, asks 12 questions like "Should the UK have voted to leave the EU?" along with follow up options like "Yes, but we should stay in the single market".

Users can also select whether they are based in England, Scotland or Wales, though there is no option for Northern Ireland, where the main parties are different.

It's hard to make the sites truly objective though, and not everyone bases their votes on policies alone.

'Over simplistic'

Ellie Hughes, a 22-year-old London-based student, has done a few different voting quizzes, even though she knows she is planning to support the Conservatives on 8 June.

"It's just a little bit of fun," she told the BBC. "Quite a few of my friends who are staunch Tory supporters have come out with Labour a few times."

Ben Crowden, a 26-year-old writer from Bristol, is a fan of the sites because they make you "really think about what you believe on quite a few issues". But he doesn't think they have ever swayed his vote.

He recently filled out a quiz which said he should vote Conservative. On various policy areas, like defence, Theresa May's party most closely matched his beliefs, he says.

But he's not going to vote Tory on 8 June. "Labour's values are much more important to me. I think [these quizzes] can be a bit over simplistic."

Dr Rob Ford, a politics professor at Manchester University, agrees.

Such quizzes, he says, rely on the "the premise that people's political decisions are based on the policy content that parties offer. But I think that's not true as much of the time as people would like to think it is. Very often, people are flattering themselves".

He's sceptical that people really change their minds based on voting quizzes, though believes they could play a positive role. "People make the same decisions, but perhaps with more information in their heads."

Matt Morley, the founder of GE2017, agrees the websites have their limitations.

"We're no substitute for talking to candidates directly, reading the news or debating with friends," Morley admits. "We sit very much at the top of the funnel, and are often the gateway to the election for a lot of people who visit us from social media or search engines."

Image caption Two fictional quiz results -for GE2017 (left) and IsideWith (right)

But he argues his website is "open to everyone regardless of where you stand", pointing out that there are several partisan sites - mainly anti-Tory. About 250,000 people have visited his site so far, he says.

As well as policies, values and identity, party leaders also often have a big influence over how people vote.

The Conservatives have made leadership a key feature of their campaign, arguing Theresa May will be better at negotiating Brexit than Jeremy Corbyn.

She's hoping to win votes from other parties based on this issue, as well as her policies. It's difficult to factor this effect into the quizzes mentioned above.

Another site, Who Should You Vote For, addresses this by asking questions about individual leaders' skills as well as policies in the abstract.

Image copyright WhoShouldYouVoteFor

One of the oldest similar sites, Political Compass, has been running since 2001.

It gives users statements to which they can agree or disagree, like "The death penalty should be an option for the most serious crimes," or "The rich are too highly taxed".

It then outputs a position on a "compass" with two axes: an economic scale spanning from left to right, and a social scale spanning from libertarian to authoritarian. It has tried to judge where the main UK parties sit.

"We hold that left and right remain very important measures. It's just that they relate solely to economics and not to social positions, hence our second dimension," says David Wayne, who says his site is not a "quiz" as such.

They are getting about 16,000-20,000 visitors a week at the moment, but Wayne says he expects that to climb sharply in the run up to polling day, as it did before recent polls in France and the US.

Political Compass has tried to judge where the main UK parties sit. But we don't all see left and right, libertarian and authoritarian, in exactly the same way.

All these sites say they are non-partisan, and many have extensive "FAQ" sections dealing with accusations of bias.

But subtle wording shifts can change how people respond to questions, according to the polling company YouGov.

They found that when people are polled on whether the BBC licence fee is good value for money, people were far more likely to say yes when given the daily fee - 40p - compared with when they were given the yearly fee, currently £147.

Nuanced shifts in phrasing could also make a big difference on political quizzes. "Efficiency savings" and "investment in services" are popular. "Cuts" and "borrowing" are not.

And a policy shopping list can only go so far - perhaps you like one party's values, another's leader and a third one's policies - but if you do want to see what each party wants to do, you can get an at-a-glance round-up in the BBC's policy-by-policy manifesto guide..