Claimant seeks review of an order of the Workers’ Compensation Board (Board) that reinstated SAIF’s denial of her claim on the ground that claimant had failed to provide corroborative evidence of compensability in addition to her own evidence, as required by ORS 656.128(3). We reverse the order and remand the case to the Board for reconsideration.
Claimant, a hairdresser, is the sole proprietor of a beauty salon. She elected workers’ compensation coverage for herself under ORS 656.128(1) and (2). In April 1992, she filed a claim for a right arm and shoulder injury, which she alleged was caused by her work. SAIF denied her claim, relying on ORS 656.128(3):
“No claim shall be allowed or paid under this section, except upon corroborative evidence in addition to the evidence of the claimant.”
According to SAIF, claimant failed to present corroborative evidence that the injury was compensable. The administrative law judge (AU) set aside SAIF’s denial on the ground that the corroborative evidence requirement pertains to proof of coverage, not to proof of compensability. The Board affirmed the AU. In SAIF v. Marshall, 130 Or App 507, 510, 882 P2d 1115, rev den 320 Or 492 (1994) (Marshall I), we reversed the Board, holding that the corroborative evidence requirement of ORS 656.128(3) pertains to proof of compensability, and we remanded the case to the Board.
On remand, claimant proffered the medical reports of Dr. Rabie, who had examined her in February and March of 1992, as corroborative evidence of compensability. Based on claimant’s own account of her injury and on his examination, Rabie reported that
“all of [claimant’s] conditions are secondary to the repetitive and fast type of activity carried out in hair dressing. Unfortunately],] having worked five to six hours per day is probably a significant aggravating factor.
"* * * * *
“I believe that [claimant] suffers from a repetitive use type tendinitis * * * no doubt secondary to her work activities.”
*53The Board was of the view that, because the doctor’s opinion depended in part on a history that claimant herself had provided, the report was not “in addition to the evidence of the claimant.” It held that “the record contains no corroborative evidence of compensability, in addition to claimant’s evidence,” and reinstated SAIF’s denial.
Claimant assigns error to that holding. She contends that Rabie’s medical reports are corroborative evidence of compensability, because they are “different in character [from claimant’s evidence] and tend to confirm claimant’s testimony on the compensability of her claim.” SAIF argues that those medical reports are not corroborative evidence, because they “cannot confirm [that] the activity occurred at work,” and do “not tend to strengthen or confirm the occurrence of the activity.” Furthermore, SAIF argues, Rabie’s reports are “not additional evidence, because [they have] claimant as [their] only source.”
Other than in Marshall I, the meaning of the term “corroborative” as used in ORS 656.128(3) has not been considered in the cases, nor is it defined in the statute. In Marshall I, 130 Or App at 510, we said that the evidence must be corroborative of compensability. We did not discuss, however, what kind of evidence would be considered corroborative of compensability. As required by PGE v. Bureau of Labor and Industries, 317 Or 606, 610-12, 859 P2d 1143 (1993), in interpreting the statute, we begin with its text, construing words of common usage according to their plain, natural and ordinary meaning. According to Webster’s Third New World Dictionary 512 (1971), “corroborative” means “tending to make more certain.” Black’s Law Dictionary 414 (rev 4th ed 1968), defines “corroborating evidence” as
“[e]vidence supplementary to that already given and tending to strengthen or confirm it; additional evidence of a different character to the same point.”
As reflected in the dictionary definitions, in the context of ORS 656.128(3), the ordinary meaning of the term corroborative evidence is evidence, different from the evidence of the claimant, that tends to make more certain the compensability of the claim. Thus, any evidence that makes more certain *54either the “arising out of’ or “in the course of’ prong of compensability is corroborative.1
The parties appear to agree that, as used in the statute “the evidence of the claimant” is something narrower than all the evidence put forth by a claimant. We need not define the precise limits of that phrase for the purpose of this case, however. SAIF asserts that the corroborating evidence must be in addition to claimant’s own statements concerning her condition, including the medical history that she provided to her physician. We accept that premise for the sake of this discussion. SAIF takes the view that, because the doctor’s opinion depended in part on the history that claimant herself had provided, the medical reports are not in addition to claimant’s own statements and for that reason are not corroborative. That is wrong. Certainly, a doctor relies on a patient’s history to formulate a medical opinion; but the opinion itself, as to diagnosis, causation and treatment, is the doctor’s opinion, based collectively on the patient’s history, a physical examination and the doctor’s own expertise. The doctor’s reports are evidence “in addition to” the claimant’s evidence.
Not only are the medical reports “in addition to” claimant’s statements, they do, in fact, corroborate compensability. They show that claimant described to her doctor the same employment conditions that she had reported on her claim and to which she testified. The doctor’s opinion attributes claimant’s injury and need for treatment to the employment conditions claimant described. The reports accordingly corroborate both the “arising out of’ and “in the course of’ components of proof of compensability, ORS 656.005(7), and satisfy the requirement of ORS 656.128(3), because they make more certain the compensability of the claim. In the light of our disposition of this first assignment of error, we need not consider the second assignment.
Reversed and remanded to Workers’ Compensation Board for reconsideration.
The dissent and the majority part ways here, the dissent concluding that both prongs must be corroborated. In our view, evidence that corroborates either prong makes compensability more certain.