— The issue in this appeal is whether the law which criminalizes the sexual exploitation of minors, RCW 9.68A, prohibited the Defendant from secretly videotaping his teenage stepdaughter, without the stepdaughter’s knowledge, while the minor was nude and partially nude.
Statutes are construed as written. RCW 9.68A.040, as written, does not prohibit the conduct involved in this case.
FACTS
Defendant Gary Chester was convicted of sexual exploitation of a minor based on his secret filming of his 14-year-old stepdaughter, while the stepdaughter was in her bedroom dressing for school.
On the morning of January 12, 1994, while the stepdaughter was in the shower, the Defendant placed a video camera under the child’s bed, aiming it toward a mirror on the closet door. The beginning of the videotape, exhibit *181, shows the Defendant setting up the camera, covering a portion of the camera with clothing or bedding, and then leaving the room. The videotape then shows Defendant’s stepdaughter walking into the room, wrapped in a towel. The tape goes on to show the stepdaughter walking in and out of the picture as she dressed. The videotape shows the stepdaughter from the front and back, both unclothed and partially clothed.
Testimony showed that the Defendant initially explained his actions as a "dumb joke” and that he was playing "Candid Camera.” According to the State’s evidence, he eventually admitted that he expected to see his stepdaughter in some state of undress because she would be coming out of the shower. He reportedly said he did not give much thought to whether she would be naked or wearing some type of underwear or bra. Police testified that he also said he thought he might see her in a pose bending over in her underwear.
A jury found Defendant Chester guilty of sexual exploitation of a minor, with a special finding that he acted with sexual motivation.1 The Court of Appeals reversed his conviction, holding there was insufficient evidence under the statute to convict. State v. Chester, 82 Wn. App. 422, 918 P.2d 514, review granted, 130 Wn.2d 1016 (1996). We granted the State’s petition for review.
ISSUE
Does the crime of sexual exploitation of a minor, as defined in RCW 9.68A.040(l)(b) and (c), prohibit the secret filming of a nude child, where the child is unaware that she is being photographed and is in a place where the child has a reasonable expectation of privacy?
ANALYSIS
The provisions of the sexual exploitation of children statute which are pertinent to this case are the following:
*19RCW 9.68A.040. Sexual exploitation of a minor—Elements of crime—Penalty.
(1) A person is guilty of sexual exploitation of a minor if the person:
(a) Compels a minor by threat or force to engage in sexually explicit conduct, knowing that such conduct will be photographed or part of a live performance;
(b) Aids, invites, employs, authorizes, or causes a minor to engage in sexually explicit conduct, knowing that such conduct will be photographed or part of a live performance; or
(c) Being a parent, legal guardian, or person having custody or control of a minor, permits the minor to engage in sexually explicit conduct, knowing that the conduct will be photographed or part of a live performance.
(2) Sexual exploitation of a minor is a class B felony punishable under chapter 9A.20 RCW.
RCW 9.68A.011. Definitions.
(3) "Sexually explicit conduct” means actual or simulated:
(e) Exhibition of the genitals or unclothed pubic or rectal areas of any minor, or the unclothed breast of a female minor, for the purpose of sexual stimulation of the viewer ....
The information initially charged the Defendant with violating RCW 9.68A.040(l)(b). The State later filed a second amended information charging the Defendant, in the alternative, with violating RCW 9.68A.040(l)(c).2
The Court of Appeals held that, under subsection Ob) of the statute, the State was required to prove that the De*20fendant initiated, influenced or otherwise caused the child to exhibit her breasts or pubic area and that the exhibition was initiated for the purpose of sexually stimulating the viewer. The Court of Appeals then held that, under the facts of this case, there was insufficient evidence to support the conviction under this subsection.
The Court of Appeals has reaffirmed its interpretation of the statute in two subsequent cases. See State v. Myers, 82 Wn. App. 435, 918 P.2d 183, review granted, 130 Wn.2d 1016 (1996), and State v. Grannis, 84 Wn. App. 546, 930 P.2d 327 (1997).3
The State argues that the Court of Appeals’ interpretation of the statute as requiring influence or communication with the child adds an element to the crime which *21the Legislature did not contemplate. The State argues that the statute prohibits all photographs of children that are taken for the purpose of sexually stimulating the viewer. Defendant Chester challenges this interpretation of the statute as unconstitutionally vague or overbroad. This statute has previously withstood constitutional challenges in this court and in the Court of Appeals. See State v. Farmer, 116 Wn.2d 414, 805 P.2d 200, 13 A.L.R.5th 1070 (1991); State v. Bohannon, 62 Wn. App. 462, 814 P.2d 694 (1991). We also have held that it does not prohibit all nude photographs of children. Farmer, 116 Wn.2d at 421. See also RCW 9.68A.001. The question before us is whether the statute prohibits a person from filming a nude child, without the child’s knowledge and where the exhibition of nudity is accomplished without the involvement of the defendant.
In determining the meaning and scope of a statute, we apply general principles of statutory construction. Those principles provide that in interpreting a statute, the fundamental duty of the court is to ascertain and carry out the intent of the Legislature. State v. Alvarez, 128 Wn.2d 1, 11, 904 P.2d 754 (1995). If a statute is unambiguous, it is not subject to judicial construction and its meaning is to be derived from the language of the statute alone. Cherry v. Municipality of Metro. Seattle, 116 Wn.2d 794, 799, 808 P.2d 746 (1991). The court may not add language to a clear statute, even if it believes the Legislature intended something else but failed to express it adequately. Adams v. DSHS, 38 Wn. App. 13, 16, 683 P.2d 1133 (1984). Additionally, a statute will be construed so as to avoid constitutional problems, if possible. New York v. Ferber, 458 U.S. 747, 769 n.24, 102 S. Ct. 3348, 73 L. Ed. 2d 1113 (1982); City of Seattle v. Montana, 129 Wn.2d 583, 590, 919 P.2d 1218 (1996).
On its face, RCW 9.68A.040(1)(b) is not ambiguous. See State v. Knutson, 64 Wn. App. 76, 81 n.4, 823 P.2d 513 (1991) (holding RCW 9.68A.040 is not ambiguous). It becomes ambiguous, and subject to constitutional chai*22lenges for vagueness, only if its language is stretched and twisted to fit facts not clearly within its scope.
The statute sets out the elements of the offense, making it a crime to (1) aid, invite, employ, authorize or cause a minor to (2) engage in sexually explicit conduct (3) knowing that the conduct will be photographed.
The words "aids, invites, employs, authorizes or causes” are not defined in the statute. In the absence of a specific statutory definition, words in a statute are given their common law or ordinary meaning. Alvarez, 128 Wn.2d at 11; State v. Smith, 117 Wn.2d 263, 271, 814 P.2d 652 (1991). A nontechnical word may be given its dictionary definition. State v. Fjermestad, 114 Wn.2d 828, 835, 791 P.2d 897 (1990).
"Aid” means to support, assist, help or strengthen. Black’s Law Dictionary 68 (6th ed. 1990); Webster’s Third New International Dictionary 44 (1986).
"Invite” means to offer an incentive or inducement or to request the participation or presence of a person. Webster’s, supra, at 1190.
"Employ” means to engage in one’s service or to hire or use. Black’s, supra, at 524; Webster’s, supra, at 743.
"Authorize” means to empower or to give a right or authority to act. Black’s, supra, at 133; Webster’s, supra, at 146.
"Cause” means to be the cause of, to bring about, to induce or to compel. Black’s, supra, at 221; Webster’s, supra, at 356.
Each of these words is an active verb. Each requires some affirmative act of assistance, interaction, influence or communication on the part of a defendant which initiates and results in a child’s display of sexually explicit conduct.
In this case, the Defendant placed a camera under his stepdaughter’s bed, hoping and expecting to catch her on film in a state of undress. Although he intended to observe her, he did not communicate with her in any way *23and he did not assist her in any way. There is no evidence in the record that the Defendant aided (supported or helped), invited (requested or induced), employed (hired or used), authorized (empowered or gave a right) or caused (brought about, induced or compelled) his stepdaughter to engage in sexually explicit conduct. If it had intended to criminalize the secret filming of a nude child who is unaware of the filming, the Legislature could have included the kind of conduct that occurred here within the prohibitions of the statute. As it exists, however, it does not appear that the Legislature intended, under the current provisions of the sexual exploitation of minors statute, to criminalize the photographing of a child, where there is no influence by the defendant which results in the child’s sexually explicit conduct. It further appears that the Legislature has not contemplated this kind of conduct would constitute a class B felony.4
Defendant Chester was alternatively charged under RCW 9.68A.040(l)(c), which prohibits a parent from permitting the minor to engage in sexually explicit conduct knowing that the conduct will be photographed. "Permit” is not defined in the statute. Its dictionary definition is to expressly or formally consent, to allow, or to acquiesce by failure to prevent. Black’s, supra, at 1140; Webster’s, supra, at 1683. While "permit” may suggest passive conduct, it appears that the aim of subsection (c) of the sexual exploitation statute is to prohibit a parent from allowing a child to be exploited under subsection (a) or (b) of the statute. The language of the statute does not support a contrary interpretation. If a parent, or stepparent, were actively involved in causing the exhibition or other sexually explicit conduct, then the parent would be subject to the terms of subsection (a) or (b). We interpret RCW 9.68A.040(l)(c) to prohibit the parent’s knowing fail*24ure or refusal to protect his or her child from sexual exploitation by another.
CONCLUSION
We hold that the Defendant’s conduct, although contemptible, does not fall within the prohibitions of the sexual exploitation of minors statute.
Affirmed.
Durham, C.J., and Smith, Johnson, Madsen, and Sanders, JJ., concur.