What is the test for jury bias in a civil case?

A defendant has a constitutional right to a trial by an impartial jury. (People v. Cissna (2010) 182 Cal.App.4th 1105, 1115.) The jury must decide the case solely on the evidence adduced at trial, and must not be influenced by any extrajudicial communications. (Ibid.) The existence of juror misconduct creates a rebuttable presumption of prejudice; the presumption is rebutted if the record shows no substantial likelihood of juror bias. (Id. at p. 1116.) Juror bias exists if there is a substantial likelihood that a juror's verdict was based on an improper outside influence, rather than on the evidence and instructions presented at trial, and the nature of the influence was detrimental to the defendant. (Ibid.) If the record shows a substantial likelihood that

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