dissenting.
The majority states the issue to be decided in this case as follows:
“When, after an expert witness has qualified, can a trial court properly exclude testimony of the expert witness?”
*261More specifically, however, this ease presents the following four issues for decision:
(1) After an expert witness has qualified, does the trial court have unlimited discretion to exclude testimony of the expert witness, or must the trial court apply what the majority refers to as the correct “principles of law” in making that decision, with the result that “he is not free of revision or review,” and will he reversed if he applies wrong “principles of law” in excluding such testimony?
(2) If so, what are the correct “principles of law” which (according to the majority) the trial judge “must apply” in making a decision whether to admit or exclude the testimony of a qualified expert witness in such a case?
(3) Did the trial judge apply the correct “principles of law” in making that decision in this case?
(4) If not, can this court affirm the exclusion of this testimony, or must it reverse and remand this case for a new trial with instructions to the trial judge to either admit this testimony or to consider and apply the correct “principles of law” in deciding whether to admit or exclude such testimony?
1. The trial judge does not have unlimited discretion to admit or exclude expert testimony, but must admit such testimony if admissible on application of the proper “rule of law.”
On the first of these four issues the majority holds, and properly so, in my opinion, that this is not a case in which a trial judge has complete and absolute discretion (described by the majority as “an exclusive power of free decision not revisible or reviewable by an appellate court in the absence of abuse”). On the contrary, the majority properly holds that in this case *262the decision to be made by the trial judge in the admission or exclusion of the testimony of this admittedly qualified expert witness was “not singularly a matter of discretion, but a question of law calling for an application of a rule of law to a particular set of facts” and that its decision on this question is “not free of revision or review.”
It follows, under the majority opinion, that the trial judge must be reversed in this case if he did not apply correct “principles of law” in excluding such testimony.①
2. The “principles of law” which “must” be applied in this case are that expert testimony is admissible whenever it can be of “appreciable help,” “assistance” or “aid” to a jury.
On the second of these four issues the majority holds, and also properly, in my opinion, that the cor*263rect “principle of law” wbicb “must” be applied by tbe trial judge in tbis case is as follows, as stated in 7 Wigmore, Evidence (3d ed) 21, § 1923:
“But tbe only true criterion is: On this subject can a jury from this person receive appreciable help ? In other words, tbe test is a relative one, depending on tbe particular subject and tbe particular witness witb reference to that subject * * *.”②
As tbe majority correctly points out, tbis is also tbe rule approved by tbis court, at least in effect, in Sandow v. Weyerhaeuser Company, 252 Or 377, 380, 449 P2d 426 (1969), thereby rejecting tbe rule adopted in earlier decisions by tbis court under wbicb tbe testimony of an expert witness must be excluded unless “required” to enable tbe jury to understand tbe problem presented which must be of such a nature or so complicated that (as stated by tbe majority) “a jury would be incapable of reaching accurate and correct conclusions without tbe benefit of such testimony.”③
*2643. The trial judge erred in excluding the expert testimony because he applied the wrong (and now rejected) “principle of law” under which such testimony must be rejected unless “required” because the jury would otherwise be “incapable” of reaching a correct result.
With all due respect, however, it is submitted that the majority has not properly considered and passed upon the third issue presented for decision in this case — whether the trial judge applied the proper and correct “principle of law” in excluding the testimony of the expert witness in this case. More specifically, the majority does not consider whether this trial judge, in excluding that testimony, applied the new and more recently approved rule, under which expert testimony must be admitted whenever it may be of “appreciable help,” “assistance” or “aid” to the jury in reaching a correct decision of the problem presented to it, or whether, in making that ruling, he applied the old and now rejected rule, under which expert testimony must be rejected unless the problem involved was of such a nature or so complicated that the assistance of an expert on that subject was “required” because the jury otherwise would be “incapable” of reaching correct or accurate conclusions on such a subject.
It follows, of course, that if the trial judge, in rejecting the expert testimony, applied the old “required” and “incapable” rule, rather than the new, “appreciable help,” “assistance” or “aid to the jury” rule, that ruling by the trial court was improper and in error, by the majority’s own opinion, for failure to apply the “correct principle of law” in making that, ruling. For the same reasons, if the trial judge re*265jeeted the expert testimony under the impression that he had free and unlimited discretion to do so, and without conscious application of the correct “principle of law,” then that ruling was also improper and in error, by the majority’s own opinion, for failure to apply the correct “principle of law.”
Accordingly, we turn to the record to determine, if possible, what, if any, “principle of law” was applied by the trial judge in rejecting the expert testimony in this case. That he did not apply the correct rule in excluding that testimony is obvious from the quotation by the majority from the statement by the trial judge of his reasons for that ruling, in which he said:
“* * * It is within the trial judge’s discretion «= * * jpkg faetnal situation, in my opinion, requires no expertise * í! * I see nothing about this particular construction which requires an expert to tell yon that it is reasonably or unreasonably safe or unsafe, so that is why I didn’t let him testify to it; * * (Emphasis added)
It is clear from this statement by the trial judge that he either was of the opinion that he had absolute and unlimited discretion to admit or reject this expert testimony or that he excluded it because of his understanding that the correct rule to be applied in making that decision was that such testimony must be rejected unless the “factual situation” was of such a nature, or so complicated, that expert testimony was “required” because the jury would be “incapable” of reaching an accurate conclusion without the benefit of testimony by an expert on the subject.
With all due respect to the majority, it is submitted that since it thus clearly appears from its own *266opinion that the trial judge applied the wrong “principle of law” in making his decision whether to admit or exclude the expert testimony in this case, the trial judge erred in making that ruling. It follows that the judgment in this case must be reversed unless this court can say, and as a matter of law, that even if the trial judge had applied the correct “principle of law,” this expert testimony must still have been excluded.
4. The expert testimony was properly admissible upon application of the correct “principle of law” because it could have been of “appreciable help,” “assistance” or “aid” to the jury.
This brings us to the fourth and final issue presented for decision in this case- — one requiring a consideration of the facts of the case, as well as the nature of the proposed testimony by the expert witness.
In considering the facts of this case it is important to bear in mind that this case involves a metal strip or “carpet bar” between the carpeting and the linoleum in a public place and extending one-half inch higher than the linoleum. In addition, it is important to bear in mind the concealed location of that protruding “carpet bar.” Thus, the carpeting extended to and slightly under the edge of the table at which plaintiff was seated, with a chair over the edge of the carpeting. The remaining space on the floor under the table was covered by linoleum, with the one-half inch “carpet bar” between the linoleum and the carpeting. Thus, when plaintiff, after being seated at the table and on that chair, attempted to push back her chair and rise, she caught her heel on the “carpet bar” and fell, according to her testimony.
*267In considering the admissibility of the expert testimony under these facts it is also important to bear in mind defendant’s explanation and defense, which was, among other things, to deny that this was improper construction or design and to contend that it is a common practice, familiar to everyone, to use such metal “carpet bars” at the edges of carpeting in public places; that plaintiff was familiar with that practice and that there was nothing improper in the construction or design of the bowling alley by the location of the “carpet bar” under the edge of the table at which plaintiff was seated.
It was in this context that plaintiff offered the following testimony by an architect who was an admittedly qualified expert witness:
“Q Now, taking into consideration the type of construction here, the vinyl and the rug and the metal strip with these chairs over there, in your opinion is this a safe practice, to put that chair over that area Í
“A No, it is not, because when you have an activity such as sitting at a table where chairs are moved and slid around, you wouldn’t have a metal edge like this in your own home around a dining-room and certainly not in a public building where you have people unfamiliar with the premises coming and moving chairs around this metal edge; when they walk up to it, they go and sit down and may be aware of the difference in color, texture of the floor coverings and be aware there is a carpet there but they would certainly not recall this at the time they sat in this fifth chair at the end of the table and had been sitting at the table for a period of time; when they would rise to go from there they would not necessarily recall that there was an unevenness in the floor and turn and be careful. The act of rising from a chair in this case, the metal edge is about where a person would place their foot *268when they rose from the chair; that the act of rising and turning, especially on one foot, you could very conceivably be off-balance if that foot were on that metal edge.
“Q Assume that the D & D Bowl had intended to use five chairs at these tables in this area and that it was designing the area for that purpose, would it have been good construction practice or a proper construction practice to have constructed the floor as shown here in these exhibits and as the floor is actually constructed at the present time?
* * * *
“A Definitely not * * *
“Q Are there any principles in construction practices in this area, Mr. Johnson, which do not permit or frown upon the use of uneven flooring in areas where people are sitting?
# & # *
“A In public areas, a person is charged with— an architect is charged with the responsibility of designing in such a manner that you do have level surfaces and avoid these hazardous conditions such as this. We do have code requirements on stairways, for example, where you have a 3/16ths of an inch variation maximum on risers, which is a pretty strong requirement. * * *.”④ (Emphasis added)
The majority quotes four full pages of the offer of proof (including this testimony) and then, without reference to or analysis of any specific testimony, *269•would summarily dismiss the entire offer of proof by the statement that “it offers nothing to aid or help the jury to conclude the ultimate question framed by the pleadings; Was this faulty construction, therefore, constituting negligence?”
In Naney v. Lane, 247 Or 367, 428 P2d 722 (1967), plaintiff’s decedent fell down a flight of stairs. On the edge of one of the top steps was a raised aluminum strip, claimed to be the cause of the fall. The majority opinion concedes that under the facts of that case it was proper for the trial judge to permit an architect to testify that in his opinion such a condition “could catch something, on the shoes of anyone going down the steps” and was “not a safe design.”
In numerous cases in other states involving safety of design and construction expert witnesses have been permitted to testify that such design or construction was, or was not safe, in the opinion of such experts.⑤ None of these cases or other authorities on *270this question was referred to or given any consideration by the majority opinion.
Indeed, the question presented by this case is similar to the question presented in Morgan v. Washington Trust Co., 105 R.I.13, 249 A2d 48, 51 (1969), in which the doors at the entrance of a bank were designed to swing outward and over a vestibule or platform and plaintiff, on entering the bank, fell when she “pulled” on one of these doors. In holding that the testimony of an architect was admissible in that case the court said (at p 51):
“From the pictures which are in evidence, the entranceway to defendant’s bank appears to the untutored eye to be perfectly safe. It is only when a trained individual such as plaintiff’s architect compares the outward swing of the new doors with the depth of the platform, and when he explains the difficulty encountered by a person of short stature in reaching up and pulling open the door that the hazards that may surround entry into the bank become apparent. * *
Thus, the admission of expert testimony in Naney v. Lane, supra, that the raised metal “strip” on the edge of the edge of the steps of a stairway was not a “safe design” and explaining the reasons why it was an unsafe design was consistent with the holdings of other courts in numerous similar cases.⑥
Accordingly, it is my opinion that upon application to the facts of this case of the same “correct principle of law” for application in cases involving the issue of safety of design or construction, it follows that the testimony of the architect that the construction of *271the bowling alley involved in this case did not conform to “safe” or “proper practices” or to “good architectural practices in the community” and his explanation of why it was an unsafe and hazardous design should have been admitted in this case.
It may be that a jury of ordinary persons could understand, without expert testimony, that the joining of a carpeted area to a linoleum area with a “carpet bar” one-half inch high would, or would not, be dangerous. It is my opinion, however, that the testimony of a qualified architect that such a manner of design or construction would or would not be considered by architects to be a “safe” or “proper” construction practice or one in accordance with “good architectural practice in that community,” together with his explanation of why it was or was not unsafe and hazardous, for reasons which might not occur to the ordinary person, would be of “appreciable help” to a jury in fully understanding the problem and in reaching a proper decision on that issue.⑦
This result is also consistent with cases involving issues of care, reasonableness and safety, in which it has been held by this court that practices by other employers or operators, even though not so universal as to constitute an industry-wide practice or custom *272and even though limited in number, are nevertheless admissible “as a matter of evidence assisting the jury to judge what is ordinarily safe” by showing how other operators have dealt with similar problems. Silver Falls Timber Co. v. Eastern & Western Lumber Co., 149 Or 126, 179, 40 P2d 703 (1935).
This is also consistent with the views of this •court as stated in the more recent decision of this court in Rich v. Cooper, 234 Or 300, 380 P2d 613 (1963), in which we said (at pp 311-312):
“It is stated generally that the admissibility of demonstrative evidence is within the discretion of the trial court. However, this does not mean that the trial court may arbitrarily exclude such evidence. If the evidence is material and relevant, it must be received unless there is some reason for excluding it. '* * *.” (Emphasis added)
Thus, with all due respect to the views expressed by the majority, it is my opinion that if the trial judge had applied the “correct principle of law” in this ease (which he clearly did not do), the testimony of the architect was admissible in this ease.
In concluding this opinion on this issue, however, the majority states:
“There are situations, such as Sandow, where a jury clearly is not equally well qualified and needs help to find the truth. There are also situations where a jury clearly is equally qualified without help from opinion testimony such as offered here. It is the area between the clearly qualified and the clearly unqualified where the trial jndge should be granted a certain latitude of decision in excluding or receiving expert opinion testimony.
“We feel that the facts of this case present just such a situation, and the trial judge ruled correctly *273in excluding the expert’s testimony.” (Emphasis added)
Assuming that the majority may he correct in the statement that in this “area” the trial judge should be allowed “a certain latitude of decision,” it still does follow that “the trial judge ruled correctly in excluding the expert’s testimony.” This is because, as stated by the majority, the trial judge must apply the “correct principle of law” in deciding whether to admit or exclude such testimony.
As previously demonstrated, the trial judge in this case did not exclude the testimony of this expert because he did not think that such testimony could not “help,” “assist” or “aid” the jury in understanding the extent of the hazards or in reaching a correct result upon the “ultimate question” whether there was faulty construction or design. Indeed, we do not know what the ruling of the trial judge would have been had he considered the offered testimony of this qualified architect by the application of that test — which the majority concedes to be the “correct rule of law” which a trial judge “must apply” in such a case.
Instead, the majority holds that this court may decide for itself that it was proper to exclude the testimony of this qualified architect that the placing of the one-half inch “carpet bar” under the edge of a table, with a chair over it, was not “proper” or “safe design” or in accord with good “architectural practice in the community,” as well as his testimony explaining why this concealed “carpet bar” was unsafe and hazardous. Moreover, the majority does so upon the apparent ground that this court may properly hold and, as a matter of law, that such testimony could not “help,” “assist” or “aid” the jury in understanding the prob*274lem and reaching a correct decision whether the “design” or “construction” was unsafe. Not only is this decision by the majority contrary to previous and recent decisions by this court and other courts (as cited above), but it would have this court usurp what the majority says is the “latitude” to be “granted” to and exercised by the trial judge in this case.
Accordingly, it is my opinion that the judgment in this case should be reversed and that this case should be remanded for a new trial, either with instructions to admit the offered testimony of the architect or with instructions that the trial judge must reconsider the admissibility of that testimony by proper application of what the majority holds to be the correct “principle of law” which the majority says “must be applied” by the trial judge in this case.
The admission of expert testimony on matters involving safety of design or construction is not exclusively for the benefit of plaintiffs. Expert testimony that design or construction is safe or in accordance with good architectural practice, when offered by defendants, is subject to the same rule.
It may be that the holding by the majority that the trial judge must be affirmed in this case for excluding almost the same identical expert testimony relating to the safety of construction or design of a raised metal strip that the trial judge in Naney v. Lane, supra, was affirmed for admitting may serve to bolster the prerogatives of trial judges. In my opinion, however, the more important consideration is that it is not in the best interests of either lawyers or litigants ■ — or in the interests of the public in good judicial administration — to establish a precedent under which one judge will be affirmed for rejecting the same evidence *275that another judge was affirmed for admitting (in Naney v. Lane, supra). Such a result is also directly contrary to the proper meaning of “judicial discretion,” expressly recognized by the majority and as previously defined by this court in State v. Lewis, supra.
For all of these reasons, I most respectfully dissent from both the views expressed by the majority opinion and the result reached by the majority in this case.
O’Connell, C.J., and Holman, J., join in this dissent.This is in accord with the view expressed by this court in State v. Lewis, 113 Or 359, 364, 230 P 543, 232 P 1013 (1924), as follows:
“Discretion is the power exercised by courts to determine questions to which no strict rule of law is applicable, but which from their nature and the circumstances of the case are controlled by the personal judgment of the court: Bouvier’s Law Diet. It cannot be exercised where a strict rule of law is applicable as the term ‘discretion’ implies the absence of any such rule. Where there is a clearly defined and well-settled applicable rule of law the courts are bound to enforce the rule and discretion is at an end. Discretion, however, is not an arbitrary and unrestricted power, but must be exercised according to fixed and settled rules.
“Dean Pound, in his Readings on the History and System of the Common Law, at page 19, says: ‘Four propositions may be laid down with reference to the exercise of discretion: (1) Whether or not a matter is one for law or for discretion is settled by law, and the court has no power to put it in the one category or the other at pleasure. A court has no discretion to apply the law or not as it sees fit. * * *.’ ” (Emphasis added)
This result is also in accord with the following conclusions, as stated by McCormick, Opinion Evidence in Iowa, 19 Drake L Rev 245 (1970), at p 257:
“The requirements for admissibility of expert opinion evidence require that the subject matter be such that the opmion will aid the jury on some question of fact before it. Definitions sometimes contain a qualification that the opmion must be on a matter which persons without such knowledge or training cannot correctly decide. However, such definitions are a throwback to the more rigid view excluding opinion testimony except in situations of necessity. Now it seems sufficient in Iowa if the subject matter is such that it is reasonably probable the expert’s opinion will help the jury in its function in searching for the truth.” (Emphasis added)
Cases cited by the majority to that effect include Goodrich v. May et al, 121 Or 418, 255 P 464 (1927); Marks v. Columbia County Lumber Co., 77 Or 22, 149 P 1041 (1915); Nutt v. Southern Pacific Co., 25 Or 291, 35 P 653 (1894).
See also 7 Wigmore, supra, §§ 1941, 1951; Ritter v. Beals, 225 Or 504, 525, 358 P2d 1080 (1961), and Naney v. Lane, 247 Or 367, 369-370, 428 P2d 722 (1967).
In addition, the question originally asked of this witness and which was the basis for the offer of proof, was:
“Q In this area where the carpeting joins the linoleum in ithe vicinity of this particular table, and after your examination, did this conform to good architectural practices in the community and in the State of Oregon.” (Emphasis added)
Among such cases involving design or construction of stairs, steps or floors with different levels, see Morgan v. Washington Trust Co., 105 RI 13, 249 A2d 48, 51 (1969); Millar v. Tropical Gables Corp., 99 S2d 589, 590 (Fla 1958); Capital Transit Co. v. Webb, 142 F2d 757 (DC Cir 1944); McCrory’s Stores Corp. v. Murphy, 164 SW2d 735, 742 (Tex 1942); Trame v. Orpheum Theatre Co., 60 Ohio App 323, 21 NE2d 178, 180 (1939); McStay v. Citizens National Trust & Savings Bank, 5 Cal App 2d 595, 43 P2d 560, 562 (1935); and Hommel v. Badger State Investment Co., 166 Wis 235, 165 NW 20, at 22 (1917).
See also cases in which such evidence was both admitted and excluded, as cited in 146 ALR 37; 62 ALR2d 1451; 7 Wigmore, Evidence (3d ed) § 1951, note 1, pp 68-81 and 1970 Pocket Supplement, pp 25-31. See also Morris, The Role of Expert Testimony on the Trial of Negligence Issues, 26 Tex L Rev 1 (1947).
For other Oregon cases, see Nutt v. Southern Pacific Co., 25 Or 291, 296, 35 P 653 (1894); Scott v. Astoria Railroad Co., 43 Or 26, 38, 72 P 594 (1903); and Goodrich v. May et al, 121 Or 418, 420, 255 P 464 (1927), among other cases.
See also Eberle v. Benedictine Sisters, 235 Or 496, 499, 385 P2d 765 (1963). In Sandow, supra, no problem of design or construction was involved.
In Lehman v. Knott, 100 Or 59, 196 P 476 (1921), in which expert opinion testimony was rejected as “invading the province of the jury,” this court made a distinction (at p 71) between opinion testimony that surgical treatment was “proper” (held to he admissible) and treatment that was “unskillful and negligent” (held to be inadmissible). That distinction was criticized by 7 Wigmore, Evidence, supra, at p 78, with the comment: “Here are Tweedledum and Tweedle-dee in the saddle again.” Similarly, any distinction in this case between expert opinion testimony that a practice is “safe,” “proper” or “customary,” does not appear to be supported by most of the cases and authorities referred to in note 4, above.