[249]*249BRYSON, J.
Plaintiff filed this action for damages for personal injuries incurred when she fell in defendant’s bowling alley.
Plaintiff’s complaint alleges that she was seated at a table overlooking the bowling lanes; that the floor material under the table was linoleum, with carpeting “surrounding the linoleum at a different level” and with a metal strip, or “carpet bar,” between the carpeting and the linoleum. The metal strip was one-half inch, or less, higher than the linoleum. Plaintiff also alleges that she was seated on a chair “partly on the linoleum and partly on the carpet” and as she “attempted to rise from said chair and table” she “caught her heel on said metal strip and fell to the floor.”
Plaintiff charged the defendant with negligence “in constructing a floor, partly linoleum and partly carpeting, where adjoined, with a metal divider protruding above the linoleum”; in placing a chair “astride the metal divider protruding above the linoleum”; and in failing to warn plaintiff of the unsafe condition.
Plaintiff’s principal assignment of error is that the court improperly sustained defendant’s objections to the introduction of opinion testimony by an architect called by plaintiff as an expert witness.
The plaintiff made an offer of proof of the expert’s testimony subject to cross-examination, and the court stated his reason for excluding the testimony. To properly understand the question presented and the court’s ruling, it is necessary to set forth the same:
“DIRECT EXAMINATION
“Q Mr. Johnson, I don’t recall exactly what you have answered and what you haven’t. I am [250]*250going to ask you several questions concerning your visit out to the D & D Bowl. Were you out there yesterday?
“A Yes.
“Q And did you examine the floor in the area shown on Plaintiff’s Exhibit H, the closest table to you in that picture?
“A Yes.
“Q And did you examine the vinyl flooring there ?
“A Yes, sir.
“Q And the rug?
“A And found there to be a half inch difference in the height.
“Q Between the vinyl flooring and the rug?
“A And the carpet.
“Q And did you note the metal stripping there ?
“A Yes, sir.
“Q On this picture here, Exhibit H, as well as on Exhibit J and on Exhibit 1 and Exhibit 3,1 will ask you to particularly note the fact that each one of those tables shown in those pictures has five chairs at the table. Is that correct ?
“A Yes, it does.
“Q And I particularly draw your attention to the chair at the — the single chair at the end of each table which is facing the alleys of the bowling alley. Do you note that?
“A Yes, sir.
“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?
“A No, it is not, because when you have an [251]*251activity 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 ease, the metal edge is about where a person would place their foot when 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 What would be the fear that you would have if this type of use, such as is shown here, that we have been talking about were indulged in? What would you be afraid would happen?
“A Well, I would be afraid that people would slip and fall. The hazardous condition like this is asking for trouble, in my opinion.
“Q And specifically what about this construction, in your opinion, Avould make it more dangerous that people would slip and fall?
“A It’s the unevenness of the floor. If that vinyl asbestos tile had been extended two feet further out into the carpeted area, then the movement of the chair and people with their feet in rising would have been on a level surface and much easier to do so; or the carpeting could have been extended to the wall and this, again, would have resulted in a level floor; and a third way, of course, is to put [252]*252underlayment under the vinyl asbestos tile and raise that floor material up to the carpeting.
“Q Would it have been difficult to have constructed this so that the vinyl would have been on the same level as the rug?
“A No. In fact, they have a — it apparently is not relevant but there is an additional hazard going down to the stairway there at that corner where this metal occurs because people coming cut the corner and would trip on that corner. It would have been far better had that edge, line that goes along the end of the table were extended, continuous so that yon would not have that condition occurring at the head of the stairs or at the chair. Then people would have a more clearly defined line of demarkation as to where this edge was occurring. The edge in the courtroom, for example, is excellent because it occurs at the separation between the public seating area and the area of the proceedings.
“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 a 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 because as it is now constructed, it is doubtful whether it is satisfactory with four chairs because the two chairs at the end of the table are in a very similar position that when a person rises, which would be away from the bowling end or toward the end of the table, that they would be putting their foot on this uneven surface again. And certainly, with the addition of a fifth chair, that that change in elevation of the floor should occur at least two feet to three feet past the end of the table to give chairs and persons room to move on a level surface.
“Q Are there any principles in construction practices in this area, Mr. Johnson, which do not [253]*253permit or frown upon the nse of uneven flooring in areas where people are sitting?
“A Again—
“Q Public areas I am talking about.
“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. But this is generally, the type of termination for carpeting in the courtroom is acceptable in the industry as long as it is fastened and maintained in a flat-type manner.
“Q Would it, Mr. Johnson, in any way have interferred [sic] with the efficiency of the operation of the D & I) Bowl, in your opinion, or in any similar enterprise if the floor in the area that we are talking abont there had been level or, in other words, if this unevenness had been eliminated?
“A Certainly not, on the two bases we talked about or mentioned before, that the vinyl asbestos tile could have been extended two or three feet out from the end of the table, this would not have altered their operation; if the carpeting had been extended under the tables to arrive at a level floor, this may have probably been a more difficult service to maintain for food spillage.
“MB. SCHWAB: That is all I have of this witness, Your Honor.”
On cross-examination Mr. Johnson testified:
“Q Your testimony then is, as I understand it, that the condition of unsafety stems from the position of the carpeting as placed there pursuant to the design?
“A Yes.
[254]*254“Q The construction itself, so far as workmanship and safety are concerned, construction only, is good?
“A Yes.”
The trial court, in stating the reason for his ruling, stated:
“In Naney vs. Lane, they didn’t need expert testimony to say whether that stripping was dangerous or not. You and I would know it as well as the expert would know it. There is nothing inherently or hiddenly dangerous. It is something that is dangerous or not as the reasonable person looks at it. It does not mean it is error to permit the expert to give his opinion. It is within the trial judge’s discretion. ° * * The factual situation, in my opinion, requires no expertise. There is nothing hidden or latent about it which isn’t obvious to the average person as in the case of as the example I used in the construction of a bridge. That is the reason I ruled the way I did. I don’t think Naney vs. Lane says you have to have expert testimony. As a matter of fact, it says that you didn’t need expert testimony in Naney vs. Lane in so many words. There are some areas where expertise may probably invade the province of the jury and there is some area where it isn’t proper. I feel like this is one where it isn’t proper. With all due respect to Mr. Johnson, I see nothing about this particular construction which requires an expert to tell you that it is reasonably or unreasonably safe or unsafe, so that is why I didn’t let him testify to it; * *
This assignment of error raises the question: When, after an expert witness has qualified, can a trial court properly exclude testimony of the expert witness? In support of her contention that the court erred in excluding such testimony by the expert witness, plaintiff relies upon the decision of this court in Naney v. Lane, 247 Or 367, 428 P2d 722 (1967), as [255]*255holding that in such a case an architect may properly testify whether the design or installation of flooring materials is safe, in his opinion.
In Naney v. Lane, plaintiff’s husband [loss of consortium action] fell while going down a flight of stairs. He caught his heel on a metal strip which extended beyond the width of the matting on the stair tread. We held it was not error to permit “a licensed architect to testify concerning both the condition he personally observed and his opinion regarding the safety of the design or installation # * * [and] that it was proper to permit an architect to testify under certain circumstances regarding the safety of certain structural designs or installations.” (Emphasis added.) To reach this result, we quoted as follows from Ritter v. Beals et al, 225 Or 504, 525, 358 P2d 1080 (1961).
“The correct rule is that an expert’s fitness to answer opinion questions must first satisfy the discretion of the trial judge. The expert then may express an opinion on an ultimate fact if the ultimate fact cannot be equally well decided by the jury from the same evidence upon which the expert has based his opinion [Citations omitted]. The decision whether to receive the testimony should be left to the sound discretion of the trial judge i:; # (Emphasis added.)
Thus, the rule of leaving the matter to the discretion of the trial judge, under certain circumstances, was upheld. This is a departure from the earlier cases that stated the expert testimony must be “required” before it was received, reasoning that a jury would be incapable of reaching accurate and correct conclusions without the benefit of such testimony. Goodrich v. May et al, 121 Or 418, 225 P 464 (1927); Marks v. [256]*256Columbia County Lumber Co., 77 Or 22, 149 P 1041 (1915); Nutt v. Southern Pacific Co., 25 Or 291, 35 P 653 (1894).
1. Generally, when appellate courts speak of the discretion of a trial judge, they refer to an exclusive power of free decision not revisable or reviewable by an appellate tribunal in the absence of abuse. This court, as well as most other authorities, has held that this rule of discretion applies when deciding if a witness has sufficient qualifications to qualify as an expert witness on the issues in a given case. Denny v. Warren, 239 Or 401, 408, 398 P2d 123 (1964); Highway Com. v. Parker et al, 225 Or 143, 162, 357 P2d 548 (1960).
2, 3. However, this cannot be the meaning of the term “discretion” when a judge is faced with a decision whether to admit certain testimony of an expert after he has been deemed qualified. At this point, he must apply certain principles of law to his decision and he is not free of revision or review. In the case at bar, it 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. The true meaning of “discretion,” when applied to the exclusion or admission of testimony from an expert witness, would be the power to make a choice from two or more legally valid solutions if supported by the facts. Texas Indemnity Ins. Co. v. Arant, 171 SW2d 915 (Tex Civ App 1943); Louis L. Jaffe,- Judicial Control of Administrative Action (1965) at 586. When faced with an offer of proof, which may or may not be appropriate for jury consideration, the trial judge may, in certain circumstances, either admit or exclude the proffered testimony if he applies the correct principle of law and does not abuse his discretion.
[257]*257Such a situation was present in both Bitter and Naney. In those cases the trial judges decided to admit the testimony and this court upheld the admission on the basis that it was within the trial judges’ discretion.
The definitions and use of the term “discretion” are numerous, as aptly described by Eosenberg, “The Discretion of the Trial Judge and Its Implications,” 4 Trial Judges Journal No. 3, p 4 (July 1965):
“* * * Discretion * * * is a very slippery concept. * * * It occurs in a hundred forms in the trial judge’s day-to-day work, bobbing up in every state and in every court. Yet the legal literature does not analyze, define or account for it in any coherent fashion. Neither do the decided cases. They bandy the terms ‘discretion’ and ‘abuse of discretion’ incessantly, but not helpfully. Indeed, it is hard to think of a subject of comparable sweep in the law that has suffered as much neglect.”
For instance, this court stated in Watson v. Dodson, 238 Or 621, 622, 395 P2d 866 (1964):
“During the trial the plaintiff asked leave to amend his complaint to ‘conform to the proof.’ The plaintiff’s request was denied. The trial court said that the allowance of an amendment that would allege a new specification of negligence was not within the discretionary power of the court. In so holding, the court clearly misconceived the role of .judicial discretion. The court had ample discretionary authority to allow the amendment [Citing cases].”
In some cases the expert who condemns the conduct of a defendant in evaluational terms gives ambiguous testimony. The conclusion may be based on technological facts or it may be unctuous criticism.
[258]*2584. The decision of the trial judge is legally valid so long as that decision is based on the proper application of a rule of law to the facts involved. In this case the court is applying the rule of law to the proffered testimony of the expert. A close examination of the testimony, previously set forth and viewed most favorably for the plaintiff, offers nothing to aid or to help the jury to conclude the ultimate question framed by the pleadings: Was this faulty construction, therefore, constituting negligence? It is evaluational conclusions without reference to a technical or scientific opinion that would aid the jury. It could be classified as testimonial argument.
This court’s most recent expression of the rule of law to be applied is stated in Sandow v. Weyerhaeuser Co., 252 Or 377, 380, 449 P2d 426 (1969), wherein this court said:
“To warrant the use of expert opinion testimony, inferences being drawn must be so related to some science, profession, business or occupation that is sufficiently technical that a lay juror cannot be expected to be equally well qualified to form a worthwhile judgment [Citing cases]. Obviously, the question upon which the witnesses’ opinion was sought was one which the average juror, unaided, would not have the skill to decide.” 252 Or at 380. (Emphasis supplied.)
This is the rule set forth in 7 Wigmore, Evidence (3d ed) 21, § 1923:
“But the only true criterion is: On this subject can a jury from this person receive appreciable help? In other words, the test is a relative one, depending on the particular subject and the particular •witness with reference to that subject * * (Emphasis his.)
[259]*259There 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 judge 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 in excluding the expert’s testimony.
Plaintiff’s remaining assignment of error is that the trial court erred in sustaining defendant’s objections to plaintiff’s offer in evidence of a question and answer from plaintiff’s deposition, which had been omitted when defendant had offered in evidence other portions of that deposition. In support of that assignment plaintiff contends that under the terms of ORS 45.260 if part of the deposition of a party is offered in evidence by the adverse party, the other party can then offer all other parts of the deposition which are relevant to the part already offered in evidence.
ORS 45.250 (1) (b) provides that the deposition of an adverse party may be used by the other party for any purpose, including substantive admissions. Rich v. Tite-Knot Pine Mill, 245 Or 185, 201, 421 P2d 370 (1966). ORS 45.260 provides that when one party offers in evidence part of such a deposition, the other party may then offer in evidence other parts of the deposition “so far as admissible under the rules of evidence.”
[260]*2605. In this case it appears that, upon the direct examination of plaintiff, the trial court had stricken from evidence and had instructed the jury to disregard a statement by plaintiff that her heel had “tripped over the metal stripping.” Since it had apparently been conceded by plaintiff that she had not observed what it was, if anything, that she tripped over, that statement was stricken as an argumentative conclusion. No assignment of error has been taken by plaintiff from that ruling.
Later, upon offering portions of plaintiff’s deposition in evidence, defendant omitted an almost identical statement by plaintiff that she “caught [her] heel on the strip * * * [and] fell * *
Thus, the trial court had previously ruled, in effect, that such a statement was not “admissible under the rules of evidence,” within the meaning of ORS 45.260. Since, however, neither the entire transcript of testimony nor the entire testimony of the plaintiff on this subject has been included as a part of the record on this appeal, it is not possible to determine whether that ruling was in error or whether, as a result of that ruling, plaintiff suffered any substantial prejudice. Cf. Coon v. Humble, 238 Or 172, 174, 393 P2d 655 (1964). It follows that no reversible error resulted from the ruling.
The judgment is affirmed.
See C. Morris, The Role of Expert Testimony in the Trial of Negligence Issues, 26 Tex L Rev 1 (1947).