"... but sure enough as I kept on trying out different combinations on her there was definite evidence that she had a marked preference for the higher ..."
http://spice-the-cat.spaces.live.com/blog/cns!EF9F6D5F0A8A4B...

"Move things around; try out different groupings and positions."
PDF! http://www.coca.org.nz/media/files/2008/05/Tips_on_exhibitio...

"You can use such devices as grids, matrices, taxonomies, maps, flow charts, causal maps, or networks to help you try out various groupings and relationships ..."
http://www-wds.worldbank.org/external/default/WDSContentServ...

"Others are put together by having the coaches try out small groupings of players to see which players have what it takes to play on the team ..."
http://ezinearticles.com/?Is-Select-Youth-Football-Destroyin...

"and simply try out many candidate molecules until one finds one that ..."
http://linkinghub.elsevier.com/retrieve/pii/S004873339800041...

"..... try out some molecules as potential ligands."
http://doi.wiley.com/10.1002/(SICI)1521-4141(199905)29:05<17...

"I just kept on trying out a new pic and got different results."
http://www.makeup411.net/showthread.php?t=3395&page=3

"He kept on trying out different options."
http://netherlands.worldcupblog.org/?Submit=GO&s=jaliens

..

... the plants have been [refining/exploring/testing/experimenting with] new molecular variations for millions ...