OPINION

I. INTRODUCTION

A father appeals a superior court order granting long-term guardianship of his daughter to maternal relatives in another state. The father has a history of inappropriate sexual relationships and during four years of the child’s life was incarcerated following a federal conviction for transportation of child pornography. The superior court ordered the guardianship based in part on expert testimony that the father could not yet be left alone with his daughter, given the *548state 'of Ms progress with sex offender treatment, and in part because Ms probation conditions proMbited unsupervised contact with anyone under 18.

We conclude that the superior court had the statutory authority to establish a guard-iansMp' under these circumstances. But the court’s finding that the daughter was likely to suffer serious emotional or physical harm if returned to her father’s care was based in part on findings that lack the required basis in the expert testimony. We therefore remand for the superior court to consider whether the remaining findings are sufficient to support the guardiansMp order,

II. FACTS AND PROCEEDINGS

A. Facts

Dana was bom in July 2008 to Jude and Marya M.1 Marya has five ■ other children, Dana’s half-brothers and -sisters. Dana is an Indian child under the Indian Child Welfare Act (ICWA).2

1. Dana’s placement history

Dana lived with both parents for her first mne months, but Jude then took her away because of Ms concerns about Marya’s heavy drinking. Soon afterward the police began investigating Jude for possession of child pornography — explicit photographs of his teenaged half-sister. The police contacted the Office of Children’s Services (OCS), which placed Dana with Jude’s friends, the Care-lawns. Jude visited Dana several days a week until Ms arrest in November 2009. Dana was then retened to her mother’s custody and OCS closed its file. In December 2009 Jude pleaded guilty to the federal offense of transporting child pornography across state lines and was sentenced to 60 months in prison followed by five years of supervised release.

Dana lived with her mother and half-siblings for about a year and a half. OCS opened tMs case in April 2011, when Marya left the children alone in an apartment. Dana was again placed with the Carelawns until Jiily 2013, when OCS decided she should live with Marya’s sister, Natalia Winsome, in another state. Although the Carelawns wanted to adopt Dana, Natalia’s family was a priority placement under ICWA.3 The superior court upheld OCS’s transfer decision in February 2014 following a contested placement hearing, and OCS moved Dana out of state in late May to live with the Winsomes.

While living with the Winsomes, Dana was sexually abused by Natalia’s minor son Roland. When Dana told the Winsomes about the abuse in April 2015, they immediately took her to the hospital. Roland was arrested for sexual assault and removed from the home. At the time of the second termination trial Dana was still living with the Winsomes, and the entire family was participating in a state program for families suffering the effects of sexual abuse. Dana had received individual treatment as well,

2. Jude’s sexual history and treatment

Jude has a Mstory of inappropriate sexual relationships beginmng in childhood and including sex with cousins, an ex-girlfriend of Ms father, a half-sister, and (more or less contemporaneously) the half-sister’s mother, Ms former stepmother. Jude spent several years of his 60-month prison sentence at Devens Federal Medical Center in Massachusetts, which provides a voluntary program for sex-offender rehabilitation. There he was diagnosed with two paraphilic disorders; “hebephilia” because of Ms strong sexual attraction to teenaged girls and “incest” because of Ms relationsMp Mstory and sexual fantasies.

Jude successfully completed Devens’s intensive sex-offender treatment'program, and a risk assessment rated Mm as having a “Low-Moderate” risk of sexual recidivism. A Relapse Prevention Plan recommended that he “should have NO contact with any children under the age of 18 ... unless supervised by a responsible adult who is aware of [Ms] sex offense Mstory.” The Plan advised *549that if Jude were allowed to live with Dana he “should not be alone with his daughter at any time nor should he enter her bedroom” or “act as a chaperone for his daughter and her friends.” In December 2013 Jude was relocated from Devens to a halfway house in Anchorage, from which he was released in May 2014. He continued treatment locally with Dr. Allen Blair, who discharged him in January 2015 because he had completed his treatment goals.

B. Proceedings

1.First termination trial

Dana was adjudicated a child in need of aid in December 2011. OCS petitioned to terminate Jude’s parental rights in August 2012 on the grounds that Jude would “not be released until 2014, and it is at best unclear if he will have resolved his history of sexual behavior against underage female relatives by then.”4

After hearing testimony in April 2014, the superior court found five of the six elements required for termination: (1) Dana was a child in need of aid due to concerns about Jude’s sexual history; (2) Jude’s troubling conduct had not been remedied; (3) OCS had made timely and reasonable efforts to provide family support services; (4) active efforts had been made to reunify the family; and (5) termination was in Dana’s best interests.5 But the court could not find beyond a reasonable doubt one of the elements required for termination: that returning Dana to Jude’s care was likely to result in serious emotional or physical damage to her.6 Without “[an] expert witness who had performed a specific diagnostic assessment of the risk posed by [Jude],” the court had “[a] reasonable doubt about [Jude]’s capacity to change,” which precluded a finding of likely harm. The court therefore denied termination.

2.Second termination trial

. Jude and OCS could not agree on an appropriate permanency plan once Dana moved out of state to live with the Winsomes, and the superior court scheduled a second termination trial. At OCS’s request the superior court agreed to consider the alternative of a jong-term guardianship with the Winsomes. It heard evidence in October and November 2015.

Dr. Richard Lazur, who had been retained by OCS to assess Jude, testified that Jude’s risk of reoffense within a year was 3.2% and within five years was -5.9%. The superior court found that both Dr. Lazur and Dr. Blair, Jude’s treating therapist, believed that Jude continued to pose “a small' but significant risk” to Dana. Both experts “recommended a detailed transition program with safeguards to protect [Dana]” and that “any reintroduction should occur over a long period of time in a safe, therapeutically-controlled environment.”

The court again concluded that OCS had proven all but one element required for termination; it found that the likelihood of harm from Dana’s return to Jude’s care was proven by clear and convincing evidence but not beyond a reasonable doubt. The court found that “[a]ceording to Dr. Lazur, [Jude] has made outstanding progress toward recovery” and “the evidence [still] fails to show beyond a reasonable doubt that [Jude]’s conduct is unlikely to change.” The court therefore denied termination for a second time.

3.Guardianship order

Having denied termination, the court turned to OCS’s alternative request that Dana be placed in a long-term guardianship with the Winsomes. The court first determined that it was authorized to consider guardianship because Jude’s parental rights had been suspended both .by Dana’s status as a child in need of aid and by the terms of Jude’s probation, which prohibited unsupervised contact with Dana. The court made three findings required to support a guardianship order: (1) that active efforts were made and were unsuccessful; (2) that “leaving the child in the parent’s custody would *550likely cause ‘serious emotional or physical damage’”; and (3) “that appointment of a guardian would be in the child’s best interest.” The court appointed the Winsomes as Dana’s guardians until she turns 18, giving them discretion over future contact between Dana and Jude, “guided by the therapeutic recommendations for [Dana].”

Jude appeals from this order. The guardian ad litem sides with OCS in supporting the order.

III. STANDARDS OF REVIEW

“In child in need of aid cases, ‘we review the trial court’s factual findings for clear error and its legal determinations de novo.’ ”7 “We will find clear error only when a review of the entire record leaves us “with a definite and firm conviction that the superior court has made a mistake.’”8 “[I]t is the function of the trial court, not of this court, to judge witnesses’ credibility and to weigh conflicting evidence.”9 Thus, “[c]onflieting evidence is generally not sufficient to overturn a trial court’s factual findings, and we will not reweigh evidence when the record provides clear support for a trial court’s ruling.”10

“Whether a trial court’s findings are consistent with the child in need of aid” or other applicable statutes “is a question of law that we review de novo.”11 “Statutory interpretation is also a question of law,”12 for which we adopt “the rule of law that is most persuasive in light of precedent, reason, and policy.”13

“Whether the state complied with the ‘active efforts’ requirement of [ICWA] is a mixed question of law and fact.”14 “Whether a child would likely suffer serious physical or emotional harm if returned to a parent’s custody is a question of fact.”15 We review for abuse of discretion the superior court’s determination that guardianship is in the child’s best interests, though wé review any underlying findings of fact for clear error.16 “In appointing a guardian, the superior court ‘abuses its discretion if it considers improper factors, fails to consider statutorily mandated factors, or assigns too much weight to some factors.’ ”17

IV. DISCUSSION

Jude’s claims on appeal focus on the long-term guardianship order and fall into three mam categories: (A) that the order exceeded the superior court’s statutory authority, (B) that the court applied the wrong standard of proof for its finding of a likelihood of harm, and (C) that the evidence does not support the court’s findings.

A. The Superior Court Was Authorized To Establish A Guardianship Under AS 13.26.045.

Alaska Statute 13.26.045 authorizes the superior court to “appoint a guardian for *551an unmarried minor if all parental rights of custody have been terminated or suspended by circumstances or prior court order.” (Emphasis added.) Jude argues that the court lacked authority to establish a guardianship under this statute because his rights had not been terminated or suspended. He specifically challenges the court’s reliance on Dana’s CINA status as having “suspended” his rights,18 arguing that he retained “residual rights” of parenting despite OCS’s physical custody of Dana.19 Alaska Statute 13.26.045 does not define “suspended”20 and the parties dispute its meaning; we consider the meaning of a statutory term de novo.21

It is true, as Jude contends, that the parent of a child in OCS custody retains “residual rights” unless and until all parental rights are terminated; these residual rights include “the right and responsibility of reasonable visitation, consent to adoption, consent to marriage, consent to military enlistment, [and] consent to major medical treatment.”22 But rights of custody are not included in those residual rights,23 The question, therefore, is whether Jude’s custodial rights were suspended while Dana was in OCS’s custody.

“When a child is committed under AS 47.10.080(c)(1) to the department, ... a relationship of legal custody exists” between OCS and the child, imposing on OCS the daily custodial responsibilities that would otherwise be the parent’s.24 In contrast, as the superior court explained, “[Jude] has neither the right of physical custody nor any day-to-day right of legal custody. He cannot take [Dana] to the park, make her a sandwich, or tuck her in at night.” To “suspend” rights means to temporarily prevent their exercise.25 Because Jude was prevented from exercising his “parental rights of custody” once OCS took custody of Dana, his parental “rights of custody” were suspended as that term is used in AS 13.26.045.26

Jude argues that “[t]he logical extension” of this, holding is that any child custody order granting “one parent sole legal and physical custody” suspends the noncustodial parent’s rights. But the analogy to private child custody disputes is inapt, as demonstrated by the Arizona case on which Jude relies, Morales v. Glenn27 The parents in Morales had divorced, and the father was awarded sole custody of two minor children.28 After the father died the superior court ordered the children returned to the mother, but a probate court simultaneously entertained a petition for guardianship brought by the paternal grandparents, who argued that the mother’s custodial rights had been terminated by the award of sole custody to the father29 The Arizona Supreme Court held that the grand*552parents’ guardianship petition should be dismissed.30 It noted that the original custody decree “was silent as to the mother’s fitness to have custody of the children,” that she had been granted reasonable rights of visitation, and that she “regained all rights of custody ... at the time of the death of the father ... and actual custody by reason of the order of the [superior] court.”31 The court expressly rejected the idea that, absent express findings on the issue, an award of custody to one parent created a presumption that the other parent was unfit to have custody.32

The opposite is true in the case of a child in need of aid. OCS has custody only because of a judicial determination that the parent has committed conduct or created conditions that put the child’s welfare at risk.33

Jude also finds support for his argument in a regulation, 7 Alaska Administrative Code (AAC) 56.370(b), which states in part that an agency may not place a child in a guardianship without having on hand, among other things, “evidence that ...' parental rights have been terminated or suspended by the court.” Jude argues that every case to which subsection .370(b) applies involves a child that “has been, like Dana, adjudicated to be a child in need of aid,” so the regulatory requirement is superfluous if a CINA adjudication necessarily suspends parental rights. But as OCS points out, the provision applies to cases other- than CINA cases and to agencies other than OCS,34 and it simply identifies the authorization paperwork necessary for any such agency to proceed with a guardianship. The regulation does not purport to supplement the guardianship statutes by requiring an additional finding of termination or suspension.35

In sum, because Jude’s custodial rights had been suspended, the superior court did not err in concluding that it had the authority under AS 13.26.045 to appoint a long-term guardian for Dana.36

B. The Guardianship Was Not A De Facto Termination That Triggered ICWA’s Requirement That The Likelihood Of Harm Be Proven Beyond A Reasonable Doubt.

Jude argues that even if the guardianship was statutorily authorized, it was a de facto termination of parental rights for which ICWA requires a higher standard of proof. ICWA prohibits termination absent proof “beyond a reasonable doubt, including testimony of qualified expert witnesses, that the continued custody of the child by the parent ... is likely to result in serious emotional or physical damage to the child.”37 Here, the superior court found a likelihood of harm only by the lesser standard of clear and convincing evidence, which is why it refused to terminate Jude’s parental rights and ordered a long-term guardianship instead.

*553ICWA does not separately address guard-ianships but it does define four types of “child custody proceeding[s]”: (1) foster care placement, (2) termination, (3) preadoptive placement, and (4) adoptive placement,38 Included in the definition of “foster care placement” is “any action removing an Indian child from its parent ... for temporary placement in ... the home of a guardian .,, where the parent ,.. cannot have the child returned upon demand, but where parental rights have not been terminated.”39 The Winsomes’ guardianship of Dana meets this definition: Dana is being kept from her father’s home;40 she will be placed temporarily 41 in the home of a guardian; Jude cannot have her returned upon demand; and Jude’s parental rights have not been terminated.42

In support of his argument that the guardianship effectively terminated his parental rights, Jude points to our decision in D.H. v. State.43 In that case the State allowed three children in need of aid to move to Alabama with their foster family.44 We held that “[a] termination of visitation rights exists not only where the state formally obtains a termination order but also where the state’s decision as a practical matter precludes the parent from exercising his or her right of reasonable visitation.”45 Because the father was “unemployed and virtually penniless” and “lack[ed] the funds to call regularly,” we held that the out-of-state foster care arrangement “constitute[d] a de facto termination of [the father’s] visitation rights.”46 Jude argues that if the foster care placement in D.H. qualified as a de facto termination, then “surely [the] more permanent and formal break of parental rights ... in this case” by the guardianship order must do so too.

But the de facto termination in D.H. was of only one parental right, albeit an important one: the right of reasonable visitation. Whether the out-of-state placement constituted a de facto termination of all the father’s parental rights was not at issue. In another case, Nelson v. Jones, we declined to find a de facto termination of all parental rights even where the superior court denied a father any visitation until he admitted that he had sexually abused one of his children.47 We concluded that “the trial court’s, restriction on visitation [was] not, in effect, a termination of [the father’s parental rights.”48

Jude also asserts that the guardianship order “ends OCS’s custody over Dana” and “changes the legal standard” by which he can regain custody, because under AS 13.26.085,49 in order to end the guardianship, he must now carry the burden of proving “that removing Dana from the Winsomes’ care would be in Dana’s best interests.” But the fact that the guardianship modified Jude’s legal rights is not enough to make it a “termination” under federal law. ICWA recognizes that any “foster care placement” modifies parental rights, in that “the parent ... cannot have the child returned upon demand.”50 But as OCS points out, if Jude *554petitions the court for the guardians’ removal, the outcome could be “the return of Dana to Jude — something that would not be possible if Jude’s parental rights were terminated and Dana were adopted.”51

Because guardianship is a foster care placement under ICWA, the superior court was required to support the guardianship order “by clear and convincing evidence that [the father]’s continued custody of his children was likely to result in serious emotional or physical damage to them.”52 The court did not err by applying this standard when it ordered the guardianship for Dana.

C. The Superior Court Did Not Err In Its Findings Of Active Efforts, But Its Findings As To Whether Those Efforts Succeeded And Whether Dana Faces Harm If Returned To Jude’s Custody Lack The Required Expert Support.

The superior court was required to make three factual findings to support the guardianship: (1) by clear and convincing evidence that “active efforts have been made to provide remedial services and rehabilitative programs designed to prevent the breakup of the Indian family and that these efforts have proved unsuccessful”;53 (2) by clear and convincing evidence, supported by expert testimony, that “custody of the child by the parent or Indian custodian is likely to result in serious emotional or physical damage to the child”;54 and (3) by a preponderance of the evidence that the appointment of a guardian is in the child’s best interests.55 Jude argues that the court erred both because the evidence does not show that ICWA’s requirement of “active efforts” was satisfied and because the court’s “substantial harm” and “best interests” findings are not supported by the record. We agree in part.

1. The superior court did not err in finding active efforts, but its finding that they were unsuccessful requires reconsideration on remand.

Under ICWA, “[a]ny party seeking to effect a foster care placement of, or termination of parental rights to, an Indian child ... shall satisfy the court that active efforts have been made to provide remedial services and rehabilitative programs designed to prevent the breakup of the Indian family and that these efforts have proved unsuccessful.”56 “The determination of active efforts is done on a ease-by-case basis.”57 “Although ‘no pat formula exists for distinguishing between active and passive efforts,’ distinctions do exist.”58 “[A]etive efforts re-*555quire taking a parent through the steps of a plan and helping the parent develop the resources to succeed; drawing up a case plan and leaving the client to satisfy it are merely passive efforts.”59 “Whether OCS made active efforts to provide remedial and rehabilitative services designed to prevent the breakup of the Indian family is a mixed question of fact and law.”60

Jude argues on appeal that (a) the superior court should not have considered efforts provided by entities other than OCS; (b) considering only OCS’s efforts, there was insufficient evidence that active efforts were made; and (c) active efforts, if made, were successful in rehabilitating him.

a. The superior court did not err by considering efforts made by entities other than OCS.

The superior court’s active efforts finding relied in part on sex offender treatment provided by the federal treatment center in Devens. According to Jude, however, ICWA requires that OCS make all qualifying efforts itself; otherwise, he argues, OCS will be “incentiviz[ed] ... to act passively” while letting others carry the burden of rehabilitation, “which runs counter to ICWA’s text and purpose.” Because Jude’s argument asks whether the superior court’s findings complied with ICWA, we consider it de novo.61

ICWA requires the party seeking a foster care placement to satisfy the court that “active efforts have been made”;62 it does not say who must make the efforts. We have approved superior courts’ consideration of efforts made by outside entities such as the Alaska Department of Corrections, parole officers, and therapeutic courts.63 We have also noted that “the practical circumstances surrounding a parent’s incarceration — the difficulty of providing resources to inmates generally, the unavailability of specific resources, and the length of incarceration — may have a direct bearing on what active remedial efforts are possible.”64 In A.M. v. State, for example, we upheld the superior court’s active efforts finding in part because of services provided by the Department of Corrections, concluding that “[the father’s enrollment in the DOC programs necessarily reduced [OCS] ’s role in providing active remedial efforts.”65

Although AM. and other past cases have considered efforts made by various entities of the State of Alaska,66 the rationale extends to services provided by others that OCS should not be required to duplicate. It is unrealistic to expect OCS to provide rehabilitative sex offender treatment to a federal prisoner, housed out of state, while that prisoner is already engaged in a federal program of intensive sex offender therapy.67 Considering *556Jude’s treatment at Devens in the court’s active efforts analysis was not error.

b. The superior court did not err by finding that active efforts were made.

We review in their entirety the efforts made to prevent the breakup of Jude’s family, focusing first on the period of Jude’s incarceration and then on the period following his release.68 Although Jude asserts that “the record does not support the court’s finding regarding active efforts,” his argument focuses not on specific factual errors but on whether the efforts satisfy the ICWA standard. This presents a question of law.69 We conclude that OCS satisfied the active efforts requirement.

i, Jude’s incarceration

Jude was arrested in late 2009 and sentenced in August 2010. OCS took custody of Dana in April 2011 and still had custody of her when Jude was released from the Anchorage halfway house in May 2014. The evidence supports the superior court’s finding that active efforts were made during this time.

As noted above, Jude received intensive sex offender rehabilitation treatment while at Devens, and he also participated in parenting and anger management classes. He was able to send Dana gifts and letters and had regular telephone contact with her while she lived with the Carelawns and the Winsomes. OCS apparently had no role in facilitating these contacts, though it “provided [Mr. Carelawn] guidance” in initiating the telephone calls and at one point gave the Carelawns advice as to whether they should continue. Still, the superior court “assigned] significant weight to the fact that this telephone contact was consistent and continuing.” While Jude had no in-person visitation with Dana while at De-vens, “[w]e have previously found that telephonic visits with an incarcerated parent satisfied the active efforts requirement.”70 And we are reluctant to say that “active efforts” requires sending a child across the country to visit an incarcerated parent.

Jude emphasizes the minimal efforts his OCS caseworkers made to contact him while he was in prison, but the evidence supports a conclusion that this was due at least in part to the logistical challenges of his incarceration.71 The scope of the active efforts requirement was necessarily narrowed by these “practical realities].”72 OCS’s involvement during this time was minimal but not dissimilar to what we have found adequate in the past. In A.M. we upheld an active efforts finding where the father received sex offender treatment in a state prison and the child protection agency “maintained contact with [the father] while he was in treatment, generally encouraged his treatment efforts, and assisted him in arranging visitation with his children.”73 In Dashiell R. v State, we upheld an active efforts finding where the father received classes and therapy while incarcerated, “OCS staff communicated with [the father] during his incarceration,” and “OCS arranged for written exchanges and telephone visits between [the father’] and the children.”74 Like the parents in A.M. and Dashiell R., Jude received treatment while *557incarcerated and had regular contact with his child by telephone and letter; unlike in those cases, OCS in this case had little involvement in these efforts but nonetheless was not required to duplicate them. We conclude that the superior court did not err when it included these facts in the necessaiy active efforts.

ii. After Jude’s release

In the few months between Jude’s release in early 2014 and Dana’s May 2014 move out of state, OCS worked on Jude’s case plan, referred him to parenting classes, and helped him to continue sex offender treatment.- He had supervised contact with Dana during family therapy sessions and at OCS,

After Dana’s move, OCS caseworker Er-yne Hughes kept in touch with Jude by email and had at least three meetings with him between November 2014 and the second termination trial in late 2015. OCS set up a risk assessment for Jude with Dr. Lazur to determine whether he could safely gain his daughter’s custody.

At the time of the second termination trial Jude was having telephone contact with Dana every Sunday, and OCS was communicating with Jude and the Winsomes about continuing these contacts. OCS had not paid for in-person visitation, but Dana’s therapists were recommending against it at that time. One of the therapists, Lisa Merz, testified that she needed to work with Jude before signing off on in-person visitation, but Jude’s refusal to schedule a phone call or visit Merz hindered progress. When Jude failed to schedule the call during Merz’s business hours, OCS caseworker Hughes emailed him in an attempt to ease tensions and “let[ ] him know that he really needs to do what [Dana’s] clinician is asking of him.” By the time of the second termination trial Jude still had not scheduled the telephone call, though he had left Merz a voicemail. He told Hughes that he could not afford to miss work or travel out of state; Hughes, on the other hand, testified that he could afford it but had told her the trip would be a waste of time without a guarantee of seeing his daughter. The superior court credited Hughes’s testimony on this issue because “evasiveness and some defensiveness” were a “fairly recurrent aspect of [Jude’s] testimony.” Jude does not directly, challenge this finding of fact.

We have held consistently that “[t]he- active efforts requirement does not require perfection.”75 While OCS’s efforts here may have “fall[en] short of exemplary,” 76 we conclude that the superior court did not err in finding that the “active efforts” requirement was satisfied.

c. The superior court’s finding that active efforts were unsuccessful requires reconsideration on remand.

The superior court found that although Jude has “complied with all of the [OCS] plan requirements,” it could not “declare [Jude]’s recovery a success at this time.” Jude argues that this is clearly erroneous; he contends that if active efforts were made they succeeded in rehabilitating him, allowing for the reunification of his family.

ICWA does not define “success” in the active efforts context. Jude argues in effect that efforts succeed when the parent completes each element of a case plan “to satisfaction.” But completion alone cannot define success. We have held that “[Compliance with treatment plans does not guarantee that parental rights will not be terminated because it cannot guarantee that adequate parenting skills will be acquired from the treatment regimen.”77 In V.S.B. we upheld *558termination of a mother’s parental rights even where she was able to “reduce the risk of an episode of Bipolar Disorder down to one mild episode in a ten-year span” and “[she] ha[d] done all that ha[d] been asked of her and there [was] nothing in the record to suggest that [she was] being insincere in her attempts at rehabilitation.”78 Although OCS had helped the mother complete parenting classes and mental health treatment, we upheld the superior court’s determination that “[her] parenting skills ha[d] only marginally improved and [were] not sufficient to make her an adequate parent.”79

As in non-ICWA cases, the appropriate question here “is whether [the parent] ha[s] remedied the problems that placed [his] children at risk and gained the necessary skills so that the children could be safely returned to [the parent’s] care.”80 The problems need to be not just addressed but “remedied.”

And a failure to remedy, when combined with a continuing likelihood of harm to the child, may demonstrate that active efforts did not succeed.81 The superior court found this combination of factors here. However, as discussed in the section that follows, the superi- or court’s finding of a likelihood of harm rests in part on considerations that lack support in the expert testimony. Because the court must reconsider on remand whether the evidence supports a likelihood of harm, it must also reconsider whether the active efforts in this case were unsuccessful.

2. One aspect of the superior court’s finding that Dana would likely suffer serious emotional or physical damage in Jude’s custody lacks support in the expert testimony.

Before appointing a guardian under ICWA the superior court “was required to find by clear and convincing evidence that [Jude]’s continued custody of [Dana] was likely to result in serious emotional or physical damage to [her].”82 Whether returning a child to the parent would likely cause harm is a question of fact,83 but whether the findings comport with statutory requirements is a question of law.84 The clear and convincing evidence of harm necessary to support a guardianship must include “testimony of qualified expert witnesses.”85 But ICWA “does not clarify the scope of the expert testimony required, nor does it require that the expert testimony provide the sole basis for the court’s conclusion.”86 We have interpreted ICWA to require that “[t]he expert testimony constitute! ] some of the evidence upon which the judge bases this finding. But it does not need to be the sole basis for that *559finding; it simply must support it.”87

As an alternative to Jude’s argument that the finding of harm required proof beyond a reasonable doubt (addressed above in Section IV.B), Jude contends that the finding was not supported by clear and convincing evidence. The superior court based its finding of harm on three “considerations”: (1) that Jude “still poses a significant risk of re-offense”; (2) that “there are good reasons to be cautious” about reunifying Jude with Dana given his extensive sexual history with relatives and teens and “the fact that [Dana] will be a teenager in six years”; and (3) Jude’s “inability to meet [Dana’s] caregiving needs.”

Jude first asserts that the superior court’s decision that he “poses a significant risk of re-offense” is in stark contrast with the expert testimony, pointing to Dr. Lazur’s testimony that he is a “poster boy for sex offender treatment” because of his desire to make positive changes in his life.88 Dr. Lazur concluded that the risk Jude will sexually reof-fend within five years was approximately 6%; he called this a “moderate risk.” Dr. Blair placed Jude in the “low moderate” risk category, at 2.8%.89 The superior court, however, found Jude’s risk of reoffense to be “significant” under the circumstances.

Jude takes issue with the term “significant,” analogizing that “[i]f a weather forecast calls for a 6 percent chance of rain, one would never say there is a ‘significant’ chan[c]e of rain.” OCS responds that “[a] small risk of rain may not warrant an umbrella, but a small risk that a child will be sexually abused may be cause for serious concern.” We agree that the significance of the risk depends in part on the seriousness of the harm to be avoided. And deciding whether a particular risk is significant in the context of a child in need of aid case is for the court, even if that risk has been quantified by an expert witness.90 We cannot say that the superior court clearly erred when it found that Jude posed a “significant” risk of sexual reoffense.

We are more concerned with the court’s second consideration: that because of Jude’s sexual history, the risk of sexual offense encompasses Dana as a possible victim. Dr. Lazur testified that the risk Jude would sexually offend with his daughter was essentially nonexistent. He testified that “there’s no evidence, either from the test data, the risk assessment, my judgment of looking at him and seeing where he is and seeing what he’s doing, that he poses a danger” to Dana. His opinion was based on Jude’s age, “awareness[,] and ability to control his drives” and also on Jude’s “very different” relationships with his former sexual partners — whom he viewed as “people of convenience” there to “serve his needs” — and with his daughter, whom he was motivated to care for as a parent. Dr. Blair deferred on this issue to Dr. Lazur. In short, the superior court’s conclusion that Dana was at risk of sexual abuse by her father finds no support in the expert testimony given at trial.

The court’s remaining concern, however — Jude’s “inability to meet [Dana’s] care-giving needs” — is well supported by the evidence. The court found that Jude “is simply not the kind of caregiver [Dana] needs right now.” The court referred to the testimony of Dana’s therapist, Merz, who testified that Jude “has displayed a pattern of failing to understand [Dana’s] past traumas and does not understand the child’s fears and anxieties.” 91 Merz identified these traumas, fears, and anxieties as including Dana’s sexu*560al abuse by her cousin, a “sense of abandonment and loss” due to early childhood neglect and Jude’s incarceration, and abusive experiences when she lived with the Carelawns, as well as a general “fear of the unknown.” She testified that Dana “is very vulnerable to potential abusive situations in the future.” She testified that Dana needs a “secure attachment” to her caregiver, to include “a predictable environment,” responsiveness to Dana’s “emotional needs,” and the practical ability to meet the daily routines of child care. Merz testified that Dana had “formed a secure attachment with” thb Winsomes and that Natalia Winsome was particularly “attuned to [Dana’s] emotional needs” and an essential part of the child’s ongoing therapy.

The court found that Jude, incontrast, “is neither legally nor psychologically capable of parenting [Dana].” It found that despite Jude’s positive response to treatment, he continued to “put[] his own needs and desires first.” The court noted the “narcissistic personality traits” observed by both Dr. Blair and Dr. Lazur and that Jude continued to exhibit those traits at trial. Merz’s testimony supported these findings; although she had had no direct contact with Jude, she reported that his telephone calls gave Dana “a big increase in anxiety and uncertainty” in part , because of Jude’s failure to recognize that his promises about their future together aggravated Dana’s “fear of the unknown.”

The superior court also discussed the emotional impact on Dana of any transition from the “permanency and stability” of the Winsomes’ home to the uncertainty of reunification with Jude. It noted that Jude was currently barred by law “from having unsupervised [contact] with anyone under the age of eighteen”; that both Dr. Lazur and Dr. Blair testified about the necessity of a slow reintroduction, with “a detailed transition plan with safeguards”92; and that because of this, Dana would not be able to live with Jude even after moving back to Alaska, meaning that “it will be some time before she and [Jude] can form a meaningful parent-child relationship.” The court concluded that “any move from [the Winsomes’ home state] to Alaska is likely to be disruptive to [Dana].”

In granting the guardianship, therefore, the court decided that Dana should remain with the Winsomes until Jude’s “likelihood of relapse decreases,” noting Dr. Lazur’s testimony that Jude’s statistical risk of reoffend-ing will drop by 50% five years after his release from prison. The court noted that Jude “may be ready to act as [Dana’s] father if he continues to progress.” But it also noted its continuing concern with how Jude’s narcissistic personality traits might impact his “ability to place [Dana’s] needs before his own” and his minimalization of some of his past transgressive behavior.

In sum, we see no clear error in the superior court’s conclusions (1) that Jude’s risk of sexual reoffense is “significant”; (2) that Jude is currently unable to meet Dana’s needs as her caregiver; and (3) that moving Dana from her secure environment with the Winsomes to a transitional setting with her father in Alaska would be disruptive and emotionally damaging. But given the expert testimony requirement of ICWA, it was error to rely on Jude’s sexual history and risk of sexual reof-fense as posing a particular danger to Dana; this conclusion is not supported by the expert testimony,93 The court relied on all these factors in combination to find the likelihood *561of harm. Because the question of likely harm is one of fact,94 we remand for the superior court to consider whether, consistent with our discussion above, there remains “clear and convincing evidence, including testimony of qualified expert witnesses,” that returning Dana to Jude’s custody will cause her serious emotional or physical damage.

3. The superior court did not abuse its discretion by finding that guardianship was in Dana’s best interests.

To support a guardianship order under AS 13.26.060(b) a court must find that “the welfare and best interests of the minor will be served by the requested appointment.” Jude challenges the court’s best interests finding in this case first because of the risk of sexual abuse posed by Natalia’s son Roland. The superior court found that “in spite of the risk that [Roland] will likely return to the [Winsome] house, ... guardianship with the [Winsomes] would adequately protect [Dana] from additional physical or psychological harm.”

The record supports this finding. A number of witnesses testified that the Winsomes responded immediately and appropriately to Dana’s report of abuse. The entire family participated in a program called RSafe, which included individual treatment for both Roland and Dana. Witnesses confirmed that because the reparation goal of RSafe “is always victim-centered,” any decision about whether Roland returns to the Winsome home will be based on the therapeutic recommendations for Dana.

The court also heard evidence of the small reoffense rate for child offenders generally (because they are driven by different impulses than adults are) and for RSafe graduates in particular. The court also reasoned that living in a household supervised by the adult Winsomes, even if Roland were living there too, would be a more normal family dynamic than returning to Alaska, where a “workable transition plan” had yet to be developed.

Finally, Jude relies on testimony that the Winsomes asked Dana to call them “Mom” and “Dad” in order to avoid confusing their younger son; according to Jude, “[t]his demonstrated both a desire to replace Jude with Mr. Winsome” and a failure to prioritize Dana’s needs over this “minor concern” for their son. We understand why Jude would find this troubling, but the superior court does not appear to have addressed it, and given the court’s other best interests findings it is very unlikely to have made a difference. Importantly, the court found that the Win-somes provide Dana a stable environment;95 in contrast, her therapists testified that transitioning her to her father’s care, at this stage in his rehabilitation, would be a long-term and uncertain process likely to cause her emotional harm.96

We conclude that the superior court did not abuse its discretion by concluding that guardianship was in Dana’s best interests.

y. CONCLUSION

The superior court’s long-term guardianship order is VACATED. The case is REMANDED for reconsideration of whether clear and convincing evidence, including the testimony of qualified expert witnesses, supports a finding that Dana would likely suffer serious emotional or physical damage if placed in Jude’s custody

STOWERS, Chief Justice, with whom WINFREE, Justice, joins, concurring in part and dissenting in part.

with whom WINFREE, Justice, joins, concurring in part and dissenting in part.

I disagree with this court’s resolution of the likelihood of harm issue.1 Looking at the *562superior court’s findings in their totality, it is clear to me that the superior court was not clearly mistaken in finding that Jude presents a substantial likelihood of harm to his daughter, given, among other things, the testimony of the daughter’s therapist (Merz), who — as this court observes in its opinion at pages 559-60 — “testified that Jude ‘has displayed a pattern of failing to understand [Dana’s] past traumas and does not understand the child’s fears and anxieties.’ ” This court's discussion at pages 559-60 buttresses the superior court’s finding on this issue.2

It does not matter that this testimony came from the daughter’s therapist as opposed to Drs. Blair and Lazur. Merz’s testimony is directly relevant to the issue and is compelling. Under our precedent the superi- or court is permitted to aggregate other testimony with expert testimony,3 and the court did consider the expert testimony of Drs. Blah- and Lazur. And while one might, looking at their testimony alone, find that the likelihood of the father molesting his daughter is slight, the court is not limited to considering their testimony in isolation, nor is the likelihood of the father molesting his daughter the only consideration in determining whether there is a likelihood of harm to the daughter if she were placed with her father. The testimony of Merz addressed other serious concerns about the daughter’s problems and needs and is more than sufficient to support the trial court’s factual finding that there is a serious likelihood of harm if the daughter were placed in her father’s custody. Thus, I dissent from this court’s decision on this issue.

I concur with the remainder of this court’s opinion and believe the superior court’s order granting the long-term guardianship should be affirmed.