, Bliss Riordan, Anchorage, for Appellants. Clay A. Young, Delaney, Wiles, Hayes, Reitman & Brubaker, Inc., Anchorage, for Appellees. Robert C. Bundy, Bogle & Gates, Anchorage, for Amicus Curiae Citizens Coalition for Tort Reform. Before: Rabinowitz, Matthews and Compton, Justices. [Moore, Chief Justice and Burke, Justice, not participating.] RABINOWITZ, Justice. Statewide Petroleum (Statewide) is a general contracting company specializing in gas station remodeling and service station maintenance. In 1989, Statewide was awarded a contract to remodel a Texaco station in Anchorage. This job included excavating the station's underground fuel tanks, segregating and examining the excavated dirt for contamination, disposing of the old fuel tanks, installing four new tanks, backfilling, and preparing the site for asphalt and concrete surfacing. As it had consistently done for at least the five previous years, Statewide subcontracted the excavation work to B-C Excavating (B-C). B-C was responsible for removing used fuel tanks, excavating a tank hole, and assisting in the installation of the new tanks. Allen Wichman operates backhoes for B-C. Because it did not have any cranes or qualified crane operators, B-C contracted with State Leasing & Equipment, Inc. (State Leasing) to provide a crane and operator. Richard Benner, the president of State Leasing, operated the crane during the course of the Texaco job. On July 25, 1989, Benner and Wichman were working in tandem, installing new tanks. The job required close coordination between laborers in the pits who were setting and leveling the tanks, Wichman on the backhoe, and Benner on the crane. Wichman would fill a bucket with pea gravel and Benner would lift the bucket with the crane and dump it into the pit where the laborers would pack gravel around the tanks to hold them in place. Space was limited at the site, and all parties were aware of the existence of power and telephone lines in the work area. Benner relied on an on-site signaler for directions to lift and set the tanks in the hole and to avoid the laborers when swinging his load. However, Benner had no designated spotter. Benner knew that he was required to have a spotter,1 though he did not discuss that requirement with anyone else at the site. Eventually, Wichman got out of his backhoe to inform the dump truck operators where to unload more gravel, and Benner set his bucket down away from the excavation pit and closer to the powerlines. On returning to his backhoe, Wichman grabbed the bucket attached to the crane and received a severe electrical shock. He sustained a variety of injuries. Wichman received workers' compensation benefits from his employer, B-C. He subsequently filed a complaint against Benner and State Leasing (collectively "Benner") alleging that Benner's negligence caused Wichman's injuries. Benner responded that Wichman's damages were caused, in whole or in part, by Wichman's own acts or the acts of third parties not under the defendant's control, since Wichman was working under and aware of the energized overhead lines. Benner thereafter moved for summary judgment, arguing that Wichman's claims were barred by the exclusive remedy provision of AS 23.30.055, based on his assertion that he and Wichman were co-employees of B-C. Wichman opposed the motion, and moved for partial summary judgment in his favor on the issue. The superior court denied Benner's motion and granted Wichman's motion, holding that Benner was an independent contractor. Benner requested that the superior court instruct the jury that it could apportion fault to Wichman, and to entities who were not parties to the suit.2 The superior court instructed the jury that Benner was negligent as a matter of law, and did not require it to apportion fault among non-parties to the litigation.3 The jury awarded Wichman $65,000. On appeal Benner challenges the superior court's rulings that (1) Wichman's recovery was not barred by the exclusive remedy provision in AS 23.30.055, (2) as a matter of law Wichman was not comparatively negligent, and (3) fault would not be apportioned among non- parties.4 I. THE SUPERIOR COURT DID NOT ERR IN DETERMINING THAT WICHMAN'S CLAIMS WERE NOT BARRED BY THE EXCLUSIVE REMEDY PROVISION IN AS 23.30.055 Workers' compensation is the exclusive remedy for injuries caused by an employee to "any fellow employee." AS 23.30.055. The statute does not define "employee."5 Benner argues that he and Wichman were co-employees of B-C, and therefore a judgment against Benner in tort was improper. The superior court concluded that Benner was a subcontractor, and not an employee. As both parties note, Alaska has adopted the "relative nature of the work" test for determining when a person is another's employee. See Searfus v. Northern Gas Co., 472 P.2d 966, 969 (Alaska 1970); see also 8 Alaska Administrative Code 45.890 (1991). The test has two parts: "first, the character of the claimant's work or business; and second, the relationship of the claimant's work or business to the purported employer's business." Ostrem v. Alaska Workmen's Compensation Bd., 511 P.2d 1061, 1063 (Alaska 1973). A. Character of the Business The character of claimant's work or business has three factors: "(a) the degree of skill involved; (b) the degree to which it is a separate calling or business; and (c) the extent to which it can be expected to carry its own accident burden." Id. 1. Degree of Skill Involved Crane operation is a skill that requires specialization. For example, union crane operators attend a school at which they learn the skills they need. B-C hired Benner, in part, because it had no qualified crane operators. At the time of trial Benner had somewhere between twenty-two and twenty-five years of experience operating cranes. Although Benner has had no formal training in crane operation, he has done considerable reading to supplement his first-hand experience. 2. Separate Business This is one of the most important factors in determining whether someone is an employee or an independent contractor: "If the worker does not hold himself out to the public as performing an independent business service, and regularly devotes all or most of his independent time to the particular employer, he is probably an employee, regardless of other factors." 1 Arthur Larson, Larson's Workmen's Compensation 45.31 (desk ed. 1993). Benner characterized himself as the owner/operator of his own business rather than as a dispatch employee. He is the president and sole shareholder of State Leasing, a business that owns five cranes and provides services. State Leasing has two business licenses and a variable number of employees, and was incorporated twenty years ago. It is a separate business from B-C. 3. Accident Burden This factor also favors a determination that Benner was an independent contractor.6 The best evidence that State Leasing was able to carry its own accident burden is that it in fact did so. At the time of the accident, it had $500,000 in liability coverage. At various times during the life of the corporation, State Leasing also had excess liability coverage. State Leasing also carried worker's compensation insurance. B. Relationship of Benner's Work to B-C's Business This factor can also be subdivided: The relationship of the claimant's work or business to the purported employer's business requires consideration of: (a) the extent to which claimant's work is a regular part of the employer's regular work; (b) whether claimant's work is continuous or intermittent; and (c) whether the duration is sufficient to amount to the hiring of continuing services as distinguished from contracting for the completion of the particular job. Ostrem, 511 P.2d at 1063. 1. Relationship Between Benner's Work and B-C's Work According to Gordon Bartel, superintendent of B-C, crane use was a "regular part of the job of removing and setting new tanks." Although B-C and State Leasing worked together frequently, State Leasing was not working exclusively for B-C in general or at the time of this job. State Leasing's account ledger for B-C indicates that B-C hired Benner a number of times during 1989 and 1990, though the engagement does not appear to have been continuous; in particular, the account reflects almost no activity between December 1988 and July 1989. B-C usually hired State Leasing when it needed a crane, but not always.7 To the best of Benner's recollection, State Leasing had two other employees around the time of the B-C job, and they were working on a different job, although one of them may have been "on call"at the precise time of the B-C job. 2. Whether the Work Was Continuous or Intermittent Benner's work took eleven hours to complete. Although an accurate statement of the duration of the larger B-C job appears to be unavailable, the job lasted at least a number of days and possibly several weeks. The work was intermittent. 3. Duration Benner was hired for the completion of a particular job. B-C had the option of terminating Ben