Majority: SAUFLEY, C.J., and CLIFFORD, DANA, CALKINS, and LEVY, JJ.
Concurrence: ALEXANDER, J.
SAUFLEY, C.J.[¶ 1] Judith A. Mitchell appeals from a judgment in favor of Dr. Francis X. Kiel-iszek, Dr. Edwin J. Krajci, and Stephens Memorial Hospital on Mitchell’s medical malpractice claim, entered after a jury trial in the Superior Court (Oxford County, Gorman, J.). Because we find no prejudicial error or abuse of discretion on any of the issues Mitchell raises on appeal, we affirm the judgment. We discuss only her *721argument that the court abused its discretion in limiting her questioning of a non-party physician during his deposition and at trial.
I. BACKGROUND
[¶ 2] A few facts in this case are undisputed. On October 1, 1999, Mitchell had a mammogram at Stephens Memorial Hospital in Norway, on a referral from her primary care physician, Dr. Kieliszek. The films were reviewed by Dr. Krajci, a radiologist at the hospital. No follow-up examination was done. Mitchell had another mammogram in August 2000 that was “clearly and unequivocally highly suggestive of malignancy” in her right breast. She subsequently underwent treatment for cancer, including surgery to remove her right breast. The parties’ views of the other relevant facts are substantially different.
[¶ 3] According to the defendant doctors and hospital, when Mitchell was undergoing the October 1 mammogram, she could not tolerate adequate compression of the breast to achieve a readable result. In reviewing the film, Krajci was concerned about an “asymmetric density” in the right breast that appeared to have possibly changed from prior years, but concluded that the mammogram was incomplete and nondiagnostic due to inadequate compression. He informally consulted with his partner Dr. Reynold Villedrouin, chief of radiology at the hospital, who agreed that there was inadequate compression for a diagnosis. Krajci examined the films with Kieliszek on October 1, told him of his concerns, and advised him that Mitchell should follow up with an ultrasound examination because she could not tolerate the compression needed for an adequate mammogram.
[¶ 4] According to the defendants, Krajci noted his conclusions on the x-ray jacket on October 1 and in his report prepared on October 4, which was sent to Kieliszek’s office. Kieliszek told Mitchell on October 4 that the mammogram had been suboptimal and nondiagnostic, and that she should have an ultrasound. His medical assistant, Cindy Ingram, told Mitchell on October 8 that she should have an ultrasound, and the hospital sent her a letter explaining that the mammogram was incomplete and nondiagnostic. Mitchell told Kieliszek that she did not want to have an ultrasound. She told Ingram that she was reluctant to have an ultrasound but would consider it and would contact Kieliszek’s office to schedule the ultrasound if she decided to have one, which she never did.
[¶ 5] According to Mitchell, she experienced severe pain during the mammogram of her right breast, but was never told that the compression was inadequate. Kielisz-ek told her that her hormone replacement therapy may have made her breasts tender and that she should stop taking the hormones two weeks before the next year’s mammogram. Ingram told her that the mammogram showed no change and that Kieliszek said it would be okay for her to have another mammogram in a year. No one told her that the mammogram was incomplete or that she should have an ultrasound.
[¶ 6] Mitchell brought this action in Superior Court in July 2003, alleging, inter aha, medical negligence by Kieliszek, Krajci, and the hospital. The court (Déla-hanty, J.) entered a standard-form scheduling order later that month that allowed the designation of one expert witness per party per issue, unless the court ordered otherwise for good cause shown. The order required Mitchell to designate her experts within three months (by the end of October 2003) and the defendants to designate theirs within five months. In September 2003, Mitchell took the deposition *722of Dr. Villedrouin. Neither she nor any of the defendants had designated Villedrouin as an expert before the deposition. At the beginning of the deposition, Mitchell’s attorney stated that an issue had arisen about the scope of the questioning and that she had telephoned the Superior Court and was hoping to have a telephone conference with the presiding justice.
[¶ 7] During the deposition, Villedrouin testified that he did not recall consulting with Krajci about Mitchell’s 1999 mammogram films. Mitchell’s attorney put a film on a light box and asked Villedrouin, “Are you able to tell from looking at the film that’s before you, the 1999 film of the right breast, ... whether there is adequate compression?” Krajci’s attorney objected and instructed Villedrouin not to answer. Mitchell’s attorney asked several more questions that Krajci’s attorney instructed Villedrouin not to answer.1 The deposition was then interrupted for a telephone conference with the court (Gorman, J.), not all of which was transcribed.
[¶ 8] The court sustained the objections, stating, “The doctor is required to answer questions regarding policies and procedures in his department ..., but he is not required to provide any expert testimony.... [I]f it’s based upon his experience or education as a radiologist, he is not required to answer.” Mitchell’s attorney asked whether she could ask Villedrouin, “[I]s there information or data here on this film that enabled you to decide whether or not there is adequacy of compression and if not what additional data would one need?” She argued that the answer would implicate Krajci’s credibility. The court ruled that the question called for an expert opinion and that Villedrouin was not required to answer. Mitchell did not, thereafter, seek to designate Villedrouin as an expert for any purpose.
[¶ 9] Before trial, Krajci filed a motion in limine to prevent Mitchell from asking Vil-ledrouin questions that would require an expert opinion. At the trial in August 2004, the court stated that its ruling from the deposition would stand, and that if Villedrouin testified that he had no recollection of consulting with Krajci on Mitchell’s 1999 films, “he’ll not be giving any expert testimony as to how he would have read the films.” Villedrouin testified, as he had in the deposition, that he did not recall the consultation recounted by Krajci. Mitchell called an expert radiologist who testified that the 1999 film of the right breast had adequate compression and was highly suggestive of malignancy.
[¶ 10] The jury returned a verdict for the defendants on Mitchell’s medical negligence claims, and the court entered judgment accordingly. Mitchell then brought this appeal.
II. DISCUSSION
[¶ 11] We review the court’s rulings limiting Mitchell’s questioning of Villedrouin during his deposition and during the trial for abuse of discretion. Searles v. Fleetwood Homes of Pa., Inc., 2005 ME 94, ¶ 80, 878 A.2d 509, 518; Corey v. Norman, Hanson & DeTroy, 1999 ME 196, ¶ 17, 742 A.2d 933, 940-41. We discuss first whether Mitchell’s questions sought to elicit an expert opinion, and then whether there *723was a sufficient basis for barring those questions.
A. Expert and Lay Opinion Testimony [¶ 12] Without objection, Villedrouin testified that he did not recall consulting with Krajci about Mitchell’s 1999 mammogram. That testimony was in the form of a simple factual statement based directly on his personal knowledge. See M.R. Evid. 602. In contrast, the disputed questions propounded by Mitchell did not seek to elicit his personal knowledge or observations. Rather, she sought to have him draw conclusions and to respond with opinions. The questions were not for that reason objectionable, but they must be judged by different standards depending on whether they sought a lay opinion under M.R. Evid. 701 or an expert opinion under M.R. Evid. 702.
[¶ 13] Rule 701 provides:
If the witness is not testifying as an expert, the witness’s testimony in the form of opinions or inferences is limited to those opinions or inferences which are (a) rationally based on the perception of the witness and (b) helpful to a clear understanding of the witness’s testimony or the determination of a fact in issue.
An opinion does not meet the standard of Rule 701 if it is “not rationally based wholly and solely on the perceptions [the witness] acquired through his personal observations.” Emery Waterhouse Co. v. Lea, 467 A.2d 986, 992 (Me.1983). “Thus, although an opinion by a lay witness may be permissible if based on his own perception, such perception must be ‘adequately grounded on personal knowledge or observation just as would be the case with simple statements of fact.’ ” Chrysler Credit Corp. v. Bert Cote’s L/A Auto Sales, Inc., 1998 ME 53, ¶21, 707 A.2d 1311, 1317 (quoting Field & Murray, Maine Evidence § 701.1 (4th ed.1997)).
[¶ 14] An expert opinion, by contrast, may be based upon facts “perceived by or made known to the expert at or before the hearing.” M.R. Evid. 703. In addition, we have said that “opinion testimony that ... is not within the common knowledge of an ordinary person ... may not be given by a lay witness.” State v. Marden, 673 A.2d 1304, 1311 n. 5 (Me.1996); accord Chrysler Credit, 1998 ME 53, ¶22, 707 A.2d at 1317 (holding that opinion that was “derived from ... specialized knowledge ... and was not within the realm of the ordinary layperson” did not qualify as lay opinion under M.R. Evid. 701). The two categories of expert and lay opinion testimony are thus mutually exclusive: an opinion based on “scientific, technical, or other specialized knowledge,” M.R. Evid. 702, cannot be an opinion of a witness “not testifying as an expert,” M.R. Evid. 701.2
[¶ 15] Mitchell argues that Villedrouin’s testimony would not have been an expert opinion because her primary purpose in questioning Villedrouin was to attempt to attack Krajei’s credibility, rather than to show that Krajci deviated from the standard of care by misreading the mammogram. She points out that if Villedrouin had testified that it was his opinion that there was adequate compression for a diagnosis, that opinion would have undermined Krajei’s testimony that he consulted with Villedrouin in 1999 and Villedrouin agreed with him that there was inadequate compression. That in turn would have *724supported Mitchell’s theory that Krajci was lying about the 1999 consultation.
[¶ 16] We need not disagree with Mitchell’s factual premises in order to reject her legal argument on this point. Nothing in the evidence rules or our case law suggests that the characterization of an opinion as lay or expert depends on the purpose for which the opinion is offered. Simply put, if an opinion requires specialized knowledge and is not based on personal perception, it is an expert opinion, even if it is offered on the “fact issue” of credibility rather than the “expert issue” of the standard of care.
[¶ 17] It is apparent, then, that Mitchell’s questions of Villedrouin did not seek a lay opinion under Rule 701. Because he had no recollection of ever seeing Mitchell’s 1999 mammogram, Villedrouin had no personal perceptions on which he could have based an opinion. In answering questions about the adequacy of compression required for a mammogram, he would not have relied on the common knowledge of an ordinary person, but on his education, training, and experience as a radiologist. The trial court thus acted well within its discretion in deciding, both during the deposition and at trial, that Mitchell’s questions called for an expert opinion.
B. Exclusion of Villedrouin’s Opinion at Trial
[¶ 18] The court would not permit Mitchell to elicit Villedrouin’s expert opinion at trial. Mitchell never designated Villedrouin as an expert witness, even though (1) it was unmistakable after the ruling during the deposition that the court believed she was seeking his expert opinion, and (2) the deadline for her to designate her experts fell more than a month after the deposition. Even after the deadline passed, Mitchell had over nine months before the trial during which she could have filed a motion asking the court to allow a late expert designation. Instead, after the deposition she did not address the issue of Villedrouin’s testimony again until, less than two weeks before the trial, she filed an opposition to Krajci’s motion in limine.
[¶ 19] We have consistently held that it is an appropriate exercise of the trial court’s discretion to exclude expert opinion testimony when the party seeking to elicit the opinion failed to designate the witness as an expert, or failed to do so in a timely fashion in accordance with pretrial scheduling orders. Moody v. Haymarket Assocs., 1999 ME 17, ¶ 8, 723 A.2d 874, 876; Pitt v. Frawley, 1999 ME 5, ¶ 9, 722 A.2d 358, 361; Black v. Ward, 633 A.2d 81, 83 (Me.1993); Stanley v. DeCesere, 540 A.2d 767, 769 (Me.1988). Indeed, when there has been a complete failure to designate an expert witness, we have concluded that it is an abuse of discretion to allow a mid-trial designation of an expert or to decline to exclude such expert testimony at trial. See Chrysler Credit, 1998 ME 53, ¶ 23, 707 A.2d at 1317-18; Stickler v. York, 566 A.2d 1385, 1388-89 (Me.1989). These precedents are controlling here. Considering the ample opportunity that Mitchell had to designate Villedrouin as an expert witness and her decision not to do so, the court did not abuse its discretion in preventing her from eliciting his expert opinion at trial.
C. Exclusion of Villedrouin’s Opinion at Deposition
¶ 20] We need not decide whether the same limitation on Mitchell’s questioning of Villedrouin was an abuse of discretion in the context of his deposition. Assuming arguendo that the court should have required Villedrouin to answer all of Mitchell’s deposition questions, the error was harmless. Even if Mitchell had been *725permitted to elicit Villedrouin’s expert opinion during his deposition, she could not have done so at trial because, as we have explained, she never designated him as an expert witness. She therefore suffered no prejudice from the court’s deposition ruling. It is highly probable that any error did not affect the outcome of the trial. See Corey, 1999 ME 196, ¶ 17, 742 A.2d at 940-41; Boccaleri v. Me. Med. Ctr., 534 A.2d 671, 673 (Me.1987).
The entry is:
Judgment affirmed.
. These included: "What information do you need in order to determine whether or not there is adequate compression?”; "Does compression tend to be the same reading both bilaterally on a single patient?”; "Does the compression remain fairly constant from year to year in any given patient?”; "Do you agree with me that the 1999 films show a change from the 1998 films?”; and "What clinical term or terms would you use to describe ... this spherical area of density that is marked with a question mark on the picture? Is that a mass?”
. This distinction, based on the language of M.R. Evid. 701 and clear in our cases, is now even more explicit in the federal rules. FED. R. EVID. 701 was amended in 2000 to add a requirement that lay opinions are limited to testimony "(c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.”