Double Olympic champion Rebecca Adlington says the World Championships in Shanghai will be a dress-rehearsal for next year's Olympic trials.
The 400m and 800m freestyle specialist will also compete in the 200m in China.
"I want to use the opportunity to see how well I can race doing all of the events," said Adlington.
"The 200m gives me an option and is an extra event to try and qualify [for 2012] in, and that's my aim, I just want to be at the Olympics."
The Mansfield-based swimmer won gold in the 400m and 800m events and bronze in the 200m at the Commonwealth Games in Delhi last year, but Shanghai will be the first time she has competed in all three at the very highest level.
"The worlds gives me a chance to try it out, to be honest the 200m is a bit of a bonus really, but I like to have a swim that's a little less pressured where people don't expect things from me."
Adlington dismissed fears that adding another race to her schedule could affect her preparations for the longer distance events.
"It will be difficult, it would be easier if the 800m was first rather than last at the Olympics, but if you have the right recovery and rest then it shouldn't be a problem."
The World Championships will also be the first opportunity for Great Britain swimmers to face opponents from the USA since GB joined their European counterparts as part of the E-Stars at the Duel in the Pool event in 2009.
"It feels like a long time since we've raced against some of the strongest teams and that's what makes it so exciting going into these Worlds because we'll be up against the Americans and the Chinese who are always strong," said Adlington.
Two years ago at the World Championships in Rome, she found herself upstaged as home favourite Federica Pellegrini became the first woman to dip under four minutes for the 400m.
Adlington says she has learnt from her mistakes and hopes Shanghai will bring better fortune.
"I didn't do very well in 2007 or 2009 so I'm hoping it's third-time lucky," she said.
"I'm not worried about the times, it's all about how I feel in the races and hopefully I can fight Pellegrini."
His greatest obstacle to reach the top of the podium this time could be 2010's triple European Champion Camille Lacourt, who after recording a time of 52.44 in the French nationals, leads this year's 100m backstroke global standings.
"Obviously Camille's been posting the fastest times in the world this year and doing a fantastic job, but there have been great performances from guys all over the world and that's what I have to chase," said Tancock.
Expectations are also high for European and Commonwealth champion Fran Halsall.
However, ankle surgery just before Christmas last year heavily disrupted her winter training and the beginning of her 2011 campaign.
Halsall made a tearful return to the pool at the World Championship trials in Manchester in March and will be competing in both the 50m and 100m freestyle races in Shanghai.
"I've only had half a year of training so I don't really see myself as a contender, but I am in great shape and just going to get in and see how quick I can go," Halsall told BBC Sport.
"It's the one chance to experience a competition that's like the Olympics before we get there, so hopefully I can do things right this time and be fully prepared for next time [in London].
Whilst Keri-Anne Payne became the first athlete to confirm her place in the Great Britain team for the 2012 Olympics by taking gold in the World Championship Open Water event, podium places do not guarantee qualification for pool swimmers.
GB can take a maximum of 26 male and 26 female swimmers to the London Games, which equates to two places in each of the individual events and a maximum of six places in the freestyle relay events.
The first trials will be held at the Olympic Aquatics Centre, on 3-10 March and for those events which do not qualify two athletes, there will then be a second opportunity at the ASA Nationals, 20-23 June.