In Boyd v. CertainTeed Corp., ___ Cal.App.4th ___ (Mar. 10, 2006), the Court of Appeal explains the difference between preserving an argument for appeal and properly presenting that argument on appeal:
[Respondent] misunderstands the concept of implied waiver, or forfeiture of a claim. “[A] reviewing court ordinarily will not consider a challenge to a ruling if an objection could have been but was not made in the trial court. [Citation.] The purpose of this rule is to encourage parties to bring errors to the attention of the trial court, so that they may be corrected.” (In re S.B. (2004) 32 Cal.4th 1287, 1293.) The critical point for preservation of claims on appeal is that the asserted error must have been brought to the attention of the trial court. (See Evid. Code, § 353, subd. (a) [evidentiary objection must be timely made and articulate specific ground for objection].) There is no requirement that a trial court objection be supported by extensive argumentation to avoid forfeiture. If an appeal is pursued, the party asserting trial court error may not then rest on the bare assertion of error but must present argument and legal authority on each point raised. (People v. Stanley (1995) 10 Cal.4th 764, 793.) This latter rule is founded on the principle that an appealed judgment is presumed correct, and appellant bears the burden of overcoming the presumption of correctness. (Kurinij v. Hanna & Morton (1997) 55 Cal.App.4th 853, 865.)
[Respondent] argues that the rule on appeal requiring claims of error to be supported by reasoned argument and legal citations extends to the trial court, and that a party forfeits a claim presented to the trial court unless the claim is supported by argumentation and citations to authority. The argument is untenable. In the appellate court, a party’s challenge to a ruling must affirmatively prove error, which necessitates argumentation and citation of authority. But in the trial court, a party’s challenge to a procedure is sufficient to preserve the issue on appeal if the challenge alerts the court to the alleged error, even without elaboration through argumentation and citation of authority.(Slip op. at 4.) It's a good thing, too, because in the middle of trial there isn't time to thoroughly brief every point, as appellate-level practice requires.