Foster (plaintiff) sued Agri-Chem, Incorporated (defendant), alleging that Agri-Chem applied too much fertilizer to Foster's land and that, as a result, Foster's crop yield was significantly reduced. At trial, Agri-Chem researchers testified they routinely conducted tests to determine the proper amount of fertilizer, and these tests showed that Foster could not have suffered the loss he claimed. The researchers testified the conditions under which their tests were conducted were similar to those under which Foster planted his crop, although there may have been immaterial dissimilarities. The judge admitted the test results, and the jury ruled in Agri-Chem's favor. Foster appealed to the Supreme Court of Oregon, arguing the judge erred in admitting the test results because Agri-Chem did not show the test conditions were substantially similar to those prevailing at the time his crop was planted.