The self-insured employer appeals the compensation judge’s findings that the employee’s actual earnings represented his earning capacity, that he had made an adequate job search, and that he had cooperated with the rehabilitation plan and, therefore, that he was entitled to temporary partial disability benefits. We affirm.

On March 9, 2004, Pierre A. Hawkins, the employee, sustained a work-related injury to his right ankle while working as a locksmith for the University of Minnesota, the employer, which was self-insured for workers’ compensation liability. The employee broke his right ankle when he slipped on ice and fell. The employer paid temporary total disability benefits to the employee from March 10, 2004, through May 2, 2004. On May 3, 2004, the employee was released to light-duty work four hours per day. The employee worked in a light-duty position from May 3, 2004, through June 4, 2004, and from June 21, 2004, through July 20, 2004, and received temporary partial disability benefits during that time. The employee continued to experience pain and was taken off work on July 21, 2004, pending ankle surgery on July 26, 2004.

On August 26, 2004, the employee’s light-duty position was assigned to a more senior employee, and since there was no other light-duty position available, the employee was laid off from his employment with the University of Minnesota. He underwent another surgery on August 1, 2005. The employee was paid temporary total disability benefits through May 16, 2006, at which time his entitlement to temporary total disability benefits expired because he had been paid the statutory maximum of 104 weeks of temporary total disability benefits. See Minn. Stat. § 176.101, subd. 1(k).

On May 24, 2006, the employee began working part time for Cook Automotive, earning a wage of $8.00 per hour, and began receiving temporary partial disability benefits based upon his earnings from Cook Automotive.

On September 11, 2006, Dr. Fernando Pena, the employee’s treating physician and also a foot and ankle specialist at Fairview University Medical Center, opined that the employee had reached maximum medical improvement (MMI) as of August 8, 2006, and that he had sustained a 2% permanent partial disability of the whole body. Dr. Pena assigned the employee permanent work restrictions of no lifting more than 20 pounds and no standing or walking more than three hours per day, but did not restrict the number of hours he could work. The employer and insurer served the employee with notice of MMI on September 21, 2006.

On November 7, 2006, the employer filed a Notice of Intent to Discontinue Benefits (NOID) on the bases that the employee’s earnings with Cook Automotive did not represent his earning capacity and that he had not performed a diligent job search. Following an administrative conference held on December 12, 2006, a compensation judge denied the employer’s request to discontinue payment of temporary partial disability benefits. The employer filed a petition for discontinuance on January 10, 2007, which was later withdrawn. On January 25, 2007, the employer filed another NOID, seeking discontinuance of temporary partial disability benefits or, in the alternative, to pay benefits based upon an imputed wage. In its NOID, the employer asserted that the employee was not engaged in a diligent job search and was not working the maximum number of hours available. The employer later filed another petition for discontinuance on March 8, 2007, asserting the same bases for discontinuance.

On February 15, 2007, the employee was examined by Dr. Mark Friedland, orthopedist, at the employer’s request. Dr. Friedland agreed with Dr. Pena’s assessment that the employee had reached MMI as of August 8, 2006, and concluded that the employee was not temporarily totally disabled from all sustained gainful employment as a result of his right foot and ankle condition. He felt the employee could work on a full-time basis, within the following restrictions: no lifting more than 50 pounds, periodic breaks every two to three hours to allow him to sit for 5-10 minutes during the work day, and avoidance of working on uneven terrain or on ladders. Dr. Friedland also opined that the employee had sustained a 4% permanent partial disability of the whole body.

A hearing was held on April 3, 2007, and post-hearing memoranda were submitted by both parties.^[1] In her findings and order, served and filed June 11, 2007, the compensation judge found that the employee’s actual earnings from Cook Automotive represented his earning capacity, that he had made an adequate job search, and that he had cooperated with the rehabilitation plan, and therefore denied the employer’s petition to discontinue temporary partial disability benefits. The employer appeals.

An employee is entitled to temporary partial disability benefits “while the employee is employed, earning less than the employee’s weekly wage at the time of the injury, and the reduced wage the employee is able to earn in the employee’s partially disabled condition is due to the injury.” Minn. Stat. § 176.101, subd. 2(b). To prove entitlement to temporary partial disability benefits, an employee must demonstrate a work-related physical disability and an actual loss of earning capacity causally related to the disability. Krotzer v. Browning-Ferris, 459 N.W.2d 509, 43 W.C.D. 254 (Minn. 1990); Arouni v. Kelleher Constr., Inc., 426 N.W.2d 860, 864, 41 W.C.D. 42, 48-49 (Minn. 1988); Dorn v. A.J. Chromy Constr. Co., 310 Minn. 42, 245 N.W.2d 451, 29 W.C.D. 86 (1976). To be entitled to temporary partial disability benefits, an employee must be gainfully employed, that is, the employee must show something more than “sporadic employment resulting in an insubstantial income.” See Schulte v. C.H. Peterson Constr. Co, 278 Minn. 79, 83, 153 N.W.2d 130, 133-134, 24 W.C.D. 290, 295 (1967); Hubbell v. Northwoods Panelboard, 45 W.C.D. 515, 517 (W.C.C.A. 1991); compare Hansford v. Berger Transfer, 46 W.C.D. 303 (W.C.C.A. 1991).

An employee’s actual earnings are presumed to be an accurate reflection of the employee’s ability to earn. Mathison v. Thermo Co., Inc., 308 Minn. 471, 243 N.W.2d 110, 28 W.C.D. 406 (1976). This presumption may, however, be rebutted by evidence that the employee’s ability to earn is different than his post-injury wage or that the reduction in the employee’s earning capacity is unrelated to the employee’s disability. Borchert v. American Spirits Graphics, 582 N.W.2d 214, 215, 58 W.C.D. 316, 318 (Minn. 1998); Wesley v. City of Detroit Lakes, 344 N.W.2d 614, 36 W.C.D. 518 (Minn. 1984). To establish an earning capacity different from actual earnings, however, there must be more presented than evidence of a hypothetical job paying a theoretical wage. Saad v. A.J. Spanjers Co., 42 W.C.D. 1184 (W.C.C.A. 1990).

The employer argues that the employee failed to establish his actual earnings. The issue of earning capacity is factual in nature and is determined by the compensation judge as the trier of fact. Mathison v. Thermal Co., Inc., 308 Minn. 471, 243 N.W.2d 110, 28 W.C.D. 406 (1976); Noll v. Ceco Corp., 42 W.C.D. 553 (W.C.C.A. 1989); see Hanmer v. Wes Barrette Masonry, 403 N.W.2d 839, 39 W.C.D. 758 (Minn. 1987); see also Serra v. Hanna Mining Co., slip op. (W.C.C.A. Apr. 12, 2005), summarily aff’d (Minn. Aug. 23, 2005). The question for this court on appeal is whether substantial evidence supports the decision of the compensation judge. Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 37 W.C.D. 235 (Minn. 1984). The employer asserts that the only evidence of the employee’s earnings presented at the hearing were his time cards, submitted by the employer. The cards had been sent to the employer by the employee to document his wages in support of his claim for temporary partial disability benefits. The employer claims that the time cards were insufficient, and that the employee did not submit pay stubs, income tax returns, bank statements, or any direct evidence of his actual earnings. The time cards submitted into evidence at the hearing, however, did contain an indication of how many hours the employee was paid for, the amount he was paid, the date he was paid, and the check number of the paycheck.

The employer also argues that the employee’s time cards were not accurate since surveillance indicated that he was at home at times when his time cards indicated he was working. The employee testified that he was able to work at home at times and that he filled out his time cards later, not contemporaneously, testimony which the compensation judge found to be credible. It is the trier of fact's responsibility to assess the credibility of a witness, Tolzmann v. McCombs-Knutson Assocs., 447 N.W.2d 196, 198, 42 W.C.D. 421, 424 (Minn. 1989) (citing Even v. Kraft, Inc., 445 N.W.2d 831, 835, 42 W.C.D. 220, 225 (Minn. 1989)), and in this case the compensation judge reviewed the time cards and concluded that the employee worked the number of hours indicated by the time cards. We will not disturb a finding based on credibility of a witness unless there is clear evidence to the contrary.

The employer also argues that the employee had not performed a diligent job search or cooperated with his rehabilitation plan. An employee released to work on a full-time basis but employed only part time may still be eligible for temporary partial disability benefits if the part-time position is all the employee is able to obtain because of the disability. See Denardo v. Divine Redeemer Memorial Hosp., 450 N.W.2d 290, 42 W.C.D. 626 (Minn. 1990). Working less than full-time may or may not be reasonable under the particular facts of the case. Kunferman v. Ford Motor Co., 65 W.C.D. 198 (W.C.C.A. 2004), summarily aff’d (Minn. Apr. 19, 2005). While a reasonable and diligent job search is not a legal prerequisite to an award of temporary partial disability benefits to an employee working part time, it is evidence which a compensation judge may consider in determining whether the employee’s wage loss is causally related to the work injury. Nolan v. Sidal Realty Co., 53 W.C.D. 388 (W.C.C.A. 1995). Other relevant evidence may include testimony about the relevant labor market, the nature of the employee’s disability, and the employee’s age, education, skills, and experience. See Jerabeck v. Teleprompter Corp., 225 N.W.2d 377, 29 W.C.D. 621 (Minn. 1977). A compensation judge may also consider such factors as the number of hours the employee worked during a pay period, the salary or hourly wage earned, the reason the employee worked less than full time, the number of hours available with the employer, and the size of the wage loss. Nolan, 53 W.C.D. at 394.

The employer argues that the employee’s failure to obtain a driver’s license when he became eligible for reinstatement in January 2007 indicates that he was not cooperating with his rehabilitation plan since having the license would have made his job search easier. The compensation judge disagreed, and found that the employee’s failure to obtain a license did not indicate non-cooperation with the plan. The employee’s rehabilitation plan did not require the employee to obtain his driver’s license once he became eligible for reinstatement, and the compensation judge concluded that the license was not necessary for the employee to cooperate with his rehabilitation plan. Substantial evidence supports this conclusion.

The employee’s job placement specialist, Ms. Kari Terwey, testified that the employee’s job placement plan and agreement indicated that the employee was to conduct a job search 3-5 hours per day, make 10-20 employer contacts per week, and arrange 1-2 interviews per week. The employee apparently met about half of these expectations. Ms. Terwey opined that the employee had made a good-faith effort given his depression and family issues. The employee’s QRC, Don Barrett, agreed with this assessment. At the time he engaged in a job search, the employee was also working part-time for Cook Automotive, and had remained subject to lifting and standing restrictions. The compensation judge concluded that,

Determinations of earning capacity are factual in nature. Einberger v. 3M Co., 41 W.C.D. 727 (W.C.C.A. 1989). It is the function of the compensation judge to determine the employee’s earning capacity. Noll v. Ceco Corp., 42 W.C.D. 553 (W.C.C.A. 1989). The issue on appeal is not whether the evidence will support a different result but whether substantial evidence supports the compensation judge’s decision. Where the evidence conflicts or more than one inference may reasonably be drawn from the evidence, the compensation judge’s findings must be affirmed. Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984). Findings of fact should not be disturbed “unless they are clearly erroneous in the sense that they are manifestly the contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.” Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975). In this case, the compensation judge heard the testimony of the employee, his job placement specialist, and his QRC, and reviewed the employee’s time cards and record of payment from Cook Automotive as well as the surveillance evidence. We cannot conclude that the compensation judge’s factual findings are clearly erroneous nor are we left with a definite and firm conviction that a mistake was committed. Accordingly, the compensation judge’s award of temporary partial disability benefits is affirmed.