Margaret Sala-mone (Salamone) appeals challenging the constitutionality of sec. 813.125, Stats. 1985, the "harassment injunction” statute. That statute sets forth the procedures for obtaining civil injunctive relief against a person who has allegedly violated the harassment statute, sec. 947.013(1).1 Salamone argues the "harassment injunction” statute 1) fails to provide sufficient notice to prepare for the final hearing on the injunction, thereby violating her rights to due process, and 2) is unconstitutionally vague and overbroad. We find the statute does provide sufficient notice, and is neither vague nor overbroad. However, because the proof offered at the hearing did not conform to the conduct alleged in the petition and because the specific injunction issued in this case was overbroad, we conclude the statute was improperly applied. Accordingly, we reverse.
Salamone and Bachowski are neighbors. Approximately two years preceding Bachowski’s petition for an injunction against Salamone, the two began feuding. The feud escalated in the summer and fall of 1985 and a number of their neighbors joined the fray. On December 5, 1985, Bachowski petitioned for a sec. 813.125, Stats., injunction ("harassment injunction”) *401against Salamone. The statute is cited in full below.2 The petition stated:
*402"My wife and I and neighbors who will be present at the hearing have been constantly har-rassed (sic) by virtue of both the actions and conduct of the respondent, including many false charges made to the Police Department of Hales Corners, Wisconsin. In addition, physical damage to property has been caused by the conduct of the respondent.”
On the day this petition was filed, the circuit court granted a temporary restraining order (TRO) ex parte based on the petition, pursuant to sec. 813.125(3), Stats. The TRO restrained and enjoined *403Salamone "from harassing John J. Bachowski in any manner” until the injunction hearing which was scheduled for December 12, 1985 at 10:30 a.m. On December 9, 1985, at 9:00 p.m., Salamone received notice of this hearing and a copy of the petition filed by Bachowski.
At the injunction hearing on December 12, Mrs. Bachowski and five neighbors testified concerning the incidents which precipitated the harassment petition. Mr. Bachowski did not testify. Review of the hearing testimony reveals that both Bachowski and Salamone may have engaged in inappropriate conduct toward each other. The neighbors and Mrs. Bachowski testified that Salamone repeatedly yelled at Bachowski, and stared at him and his family. Salamone asserted that the yelling was in response to obscene gestures and comments Bachowski made to her in the presence of her young children. It was also revealed at the hearing that charges against Bachowski for improper use of the telephone, stemming from obscene phone calls allegedly made to Salamone, were pending. The trial court acknowledged that Salamone might have a reciprocal claim for harassment and may also be entitled to an injunction under sec. 813.125, Stats. However, the trial court noted that without having filed a petition for such relief Salamone’s testimony concerning the actions of Bachowski which "harassed” her was simply not relevant to disposition of Bachowski’s injunction request.
The judge granted Bachowski’s injunction concluding that Salamone "has no right to stand out on her driveway and yell at another neighbor no matter what the relationship between those parties is.” The injunction enjoined Salamone for a period of two years from "harassing petitioner, having any contact with *404petitioner or coming upon petitioner’s premises.” This appeal followed.
Salamone argues that the statute is unconstitutional and, alternatively, that it was improperly applied. We note that neither the trial court nor court of appeals have ruled on the constitutional issues presented in this case. Nevertheless, the constitutionality of a statute is a question of law which we review de novo without deference to the lower courts’ decisions. See State v. Ludwig, 124 Wis. 2d 600, 607, 369 N.W.2d 722 (1985).
In reviewing the constitutionality of sec. 813.125, Stats., we recognize that there is a strong presumption that a legislative enactment is constitutional. State v. Cissell, 127 Wis. 2d 205, 214, 378 N.W.2d 691 (1985). The party challenging the constitutionality of a statute assumes a heavy burden of persuasion. This court has repeatedly stated that it is not enough that the challenger of a law
". . . establish doubt as to the act’s constitutionality nor is it sufficient that respondent establish the unconstitutionality of the act as a probability. Unconstitutionality of the act must be demonstrated beyond a reasonable doubt. Every presumption must be indulged to sustain the law if at all possible and, wherever doubt exists as to a legislative enactment’s constitutionality, it must be resolved in favor of constitutionality.” State ex rel. Hammermill Paper Co. v. La Plante, 58 Wis. 2d 32, 46, 205 N.W.2d 784 (1973).
With these principles in mind, we turn to the constitutional challenges to sec. 813.125 raised in this appeal. We begin with the question of whether certain procedures set forth in sec. 813.125 violate the notice *405requirements of the due process clause of the fourteenth amendment of the United States Constitution.
Salamone asserts that the summary procedures set forth in sec. 813.125, Stats., fail to allow sufficient time to prepare for the final hearing on the injunction, thereby denying her due process.
Under the statute a court may, upon the filing of a petition by a victim, issue an ex parte TRO ordering the respondent to "cease or avoid the harassment” of the victim. Section 813.125(3)(a), Stats. The judge must hold a hearing on the issuance of the requested injunction within seven days of the issuance of the TRO. Section 813.125(3)(b). One of the prerequisites to granting the injunction is that the court find that the petitioner has served upon the respondent a copy of the TRO and notice of the time for the hearing on the issuance of the injunction. Section 813.125(4)(a)3.
We acknowledge that no minimum notice period is specified in the statute but we must interpret the statute to avoid constitutional invalidity. See State ex rel. Lynch v. Conta, 71 Wis. 2d 662, 689, 239 N.W.2d 313 (1976) ("[g]iven a choice of possible interpretations, this court must select the construction that results in constitutionality rather than invalidi-ty_”). Because an alternative construction would render the statute unconstitutional, we construe notice to mean "reasonable notice,” which is all that is required by due process. E.g., Jones v. Jones, 54 Wis. 2d 41, 45, 194 N.W.2d 627 (1972). The notice must be "reasonably calculated to inform the person of the pending proceeding and to afford him or her an opportunity to object and defend his or her rights.” In Matter of Estate of Fessler, 100 Wis. 2d 437, 447, 302 N.W.2d 414 (1981). There is nothing in the statute *406which precludes the trial court from recessing the hearing until a later date if reasonable notice has not been provided to the respondent. In fact the statute precludes a judge from granting an injunction unless "notice,” which we construe as meaning "reasonable” notice, has been given to the respondent. If a judge fails to delay the hearing to afford the respondent adequate time to prepare or grants the injunction when reasonable notice has not been given to the respondent, the judge’s action may upon review be deemed an abuse of discretion. We conclude that the procedures set forth in the statute are sufficient to provide the type of notice due process requires.
We now turn to Salamone’s vagueness challenge. A statute is "unconstitutionally vague if it fails to afford proper notice of the conduct it seeks to proscribe or if it encourages arbitrary and erratic arrests and convictions.” Milwaukee v. Wilson, 96 Wis. 2d 11, 16, 291 N.W.2d 452 (1980). In State v. Popanz, 112 Wis. 2d 166, 332 N.W.2d 750 (1983) this court explained that "[t]he principles underlying the void for vagueness doctrine ... stem from concepts of procedural due process.” Id. at 172.
To survive a vagueness challenge a statute must be sufficiently definite to give persons of ordinary intelligence who wish to abide by the law sufficient notice of the proscribed conduct. Id. at 173; Wilson, 96 Wis. 2d at 16. A vague law "'may trap the innocent by not providing fair warning.’” Popanz, 112 Wis. 2d at 173 quoting, Grayned v. City of Rockford, 408 U.S. 104, 108 (1972). It must also permit law enforcement officers, judges and juries to enforce and apply the law without forcing them to create their own standards. Id. "The danger posed by a vague law is that officials *407charged with enforcing the law may apply it arbitrarily or the law may be so unclear that a trial court cannot properly instruct the jury as to the applicable law.” Id. at 173. However, it is not necessary in order to withstand a vagueness challenge, "for a law to attain the precision of mathematics or science....” Wilson, 96 Wis. 2d at 16.
Salamone contends that the statutory definition of harassment set forth in sec. 813.125(l)(b), Stats., fails to state with sufficient definiteness or certainty the specific conduct which is proscribed by the law. That section defines harassment as "[e]ngaging in a course of conduct or repeatedly committing acts which harass or intimidate another person and which serve no legitimate purpose.” Section 813.125(l)(b). We reject Salamone’s contention that this definition fails the vagueness test set forth above. Though the key words in this definition, "harass” or "intimidate” are not expressly defined in the statute, to "a person of ordinary intelligence” these words clearly connote more than mere bothersome or annoying behavior. See, e.g., People v. Malausky, 485 N.Y.S.2d 925, 928 (N.Y. Crim. Ct. 1985) ("immature, immoderate, rude or patronizing manner which annoys another is not enough ...” to establish a violation of criminal harassment statute).
Their meaning can be readily ascertained, by consulting a recognized dictionary. E.g., State v. Wickstrom, 118 Wis. 2d 339, 352, 348 N.W.2d 183 (Ct. App. 1984). "Harass” means to worry and impede by repeated attacks, to vex, trouble or annoy continually or chronically, to plague, bedevil or badger. Webster's Third New International Dictionary 1031 (1961). "Intimidate” means "to make timid or fearful.” Id. at 1184. Moreover, their meaning is narrowed by the statute’s *408requirement that the acts which harass or intimidate must be accomplished by repeated acts or a course of conduct. Section 813.125(l)(b), Stats. Thus, it is clear that single isolated acts do not constitute "harassment” under the statute. E.g., People v. Hotchkiss, 300 N.Y.S.2d 405, 407 (N.Y. Civ. Ct. 1969). The definition of harassment further requires that the harassing and intimidating acts "serve no legitimate purpose.” This is a recognition by the legislature that conduct or repetitive acts that are intended to harass or intimidate do not serve a legitimate purpose. Whether acts or conduct are done for the purpose of harassing or intimidating, rather than for a purpose that is protected or permitted by law, is a determination that must of necessity be left to the fact finder, taking into account all the facts and circumstances. See Model Penal Code sec. 250.4 comment 5, 368 (1980).
Yet another aspect of the statute narrows the meaning of "harassment.” A TRO or injunction can only be obtained if the conduct was intended to harass. Section 813.125(3) and (4), Stats., requires that a judge find reasonable grounds to believe that the respondent violated sec. 947.013, the criminal harassment statute. That section explicitly requires "intent to harass or intimidate another person. ...” Section 947.013(1). (Emphasis added.)
The legislative history of secs. 813.125 and 947.013, Stats., sheds some light on the purpose and meaning of these statutes. According to the analysis of the legislation by the Legislative Reference Bureau, Wisconsin’s harassment statute was based substantially on a New York statute. See Drafting File for 1983 Wis. Act 336, see also N.Y. Penal Law sec. 240.25 (McKinney 1987). That statute in turn was based on sec. 250.4 of the American Law Institute’s Model *409Penal Code. A review of the commentary accompanying New York’s statute and the model code indicates that the purpose of the legislation was to extend to the individual the protections long afforded to the general public under disorderly conduct or breach of peace statutes. See Model Penal Code sec. 250.4 comment 1, at 360; N.Y. Penal Law sec. 240.25 Practice Commentary, 300 (McKinney 1987). In reviewing the statute and its history it is clear the legislature has sought to prevent repeated assaults on the privacy interests of individuals without unnecessarily infringing on their freedom to express themselves through speech and conduct.
The statute’s history reveals that the legislature was attempting to define harassment with as much precision as the English language permits. The drafting file includes early drafts of the statute, modeled after the New York harassment statute, which contain much broader definitions of "harassment.” See Drafting File for 1983 Wis. Act 336. The initial Assembly version of the bill defined "harassment” as,
"1. Insulting, taunting or challenging another person in a manner likely to provoke a violent or disorderly response.
"2. Striking, shoving, kicking or otherwise subjecting the other person to physical contact or attempting or threatening to do the same.
"3. Following the other person in or about a public place.
"4. Engaging in a course of conduct or repeatedly committing acts which harass, annoy, frighten or intimidate the other person and which serve no legitimate purpose.” 1983 Assembly Bill 353.
*410Over the course of Assembly and Senate deliberations definitions (1) and (3) were dropped entirely and (4) was substantially narrowed. The legislature may have been aware that the term "annoy” had been held unconstitutionally vague by other jurisdictions, e.g., Bolles v. People, 541 P.2d 80, 82-83 (Colo. 1975), and in contrast, statutes using the term "harass” had been ruled sufficiently specific to survive constitutional challenges on vagueness grounds. E.g., State v. Hagen, 558 P.2d 750, 752 (Ariz. 1976); Commonwealth v. Duncan, 363 A.2d 803, 806-07 (Pa. Super. 1976).
We again emphasize that scientific precision in drafting is not always possible nor is it necessary for a statute to withstand a vaguéness challenge. As the United States Supreme Court explained in the context of a vagueness challenge to an obscenity statute, "lack of precision is not itself offensive to the requirement of due process. '... [T]he Constitution does not require impossible standards'; all that is required is that the language 'conveys sufficiently definite warning as to the proscribed conduct when measured by common understanding and practices....'" Roth v. United States, 354 U.S. 476, 491 (1957). (Citation omitted.)
We also agree with the authors of the Model Penal Code that the requirements of an intent to harass and the absence of any legitimate purpose for the acts, render the harassment provisions of sec. 813.125, Stats., sufficiently precise to carry fair warning to the citizenry. As the Model Penal Code authors state:
"Taken together, these elements of the offense should sufficiently flesh out its meaning to survive vagueness review. This conclusion is supported by *411the fact that it is probably impossible to do any better. There is no realistic prospect of anticipating in a series of more specific provisions all the ways that persons may devise to harass others, and without a residual offense of this sort, many illegitimate and plainly reprehensible forms of harassment would not be covered.” Model Penal Code sec. 250.4 comment 6 at 371. (Footnote omitted.)
It is clear from sec. 813.125, Stats., that chronic, deliberate behavior, with no legitimate purpose designed to harass another person is proscribed by the statute. We conclude that the legislature has defined the conduct proscribed by sec. 813.125 with sufficient specificity to meet constitutional requirements with respect to vagueness.
We now turn to Salamone’s overbreadth challenge. A statue is overbroad when its language, given its normal meaning, is so sweeping that its sanctions may be applied to constitutionally protected conduct which the state is not permitted to regulate. Wilson, 96 Wis. 2d at 19. The essential vice of an overbroad law is that by sweeping protected activity within its reach it deters citizens from exercising their protected constitutional freedoms, the so-called "chilling effect.” We reject Salamone’s argument that sec. 813.125, Stats., has a chilling effect on free speech. The intent requirement and the phrase "no legitimate purpose” make clear that protected expression is not reached by the statute. See Model Penal Code sec. 250.4 comment 6 at 371-72. It is not directed at the exposition of ideas but at oppressing repetitive behavior which invades another’s privacy interests in an intolerable manner. *412We conclude that the zone of conduct regulated by this statute is clear. It does not, by its terms, sweep within its ambit actions which are constitutionally protected so as to render it unconstitutionally overbroad.
We now address the question of whether the statute has been properly applied. We note that a constitutional statute may be improperly applied. Cf Wilson, 96 Wis. 2d at 21 ("the fact that a law may be improperly applied or even abused does not render it constitutionally invalid.”).
Salamone argues that the statute has been improperly applied in several respects: 1) the content of the notice was insufficient; 2) the proof at the hearing was insufficient; and 3) the injunction was overbroad. We will address each of these in turn.
1) THE CONTENTS OF THE NOTICE
Salamone claims that the notice was insufficient to apprise her of the nature of the claims and the evidence to be produced at the hearing, thereby leaving her to speculate about the charges she might have to defend against. We disagree.
As previously stated, due process requires that the notice provided reasonably convey the information required for parties to prepare their defense and make their objections. Estate of Fessler, 100 Wis. 2d at 446-47. We conclude that compliance with the requirements of sec. 813.125(5)(a), Stats., would provide adequate notice in this regard. That section states: "(5) Petition, (a) The petition shall allege facts sufficient to show the following: 1. The name of the person who is the alleged victim. 2. The name of the respondent. 3. That the respondent has violated s. 947.013.” This section requires a petitioner to state facts and circumstances which describe and support the specific acts or *413conduct which allegedly constitute the harassing behavior as defined by secs. 813.125(5)(a) and (b) and 947.013(l)(a) and (b). Significantly, the circuit court form which a petitioner must file to obtain a harassment TRO and injunction, requires the petitioner to specify "what happened when, where, who did what to whom.” Thus, it would be insufficient, for example, pursuant to sec. 813.125(5)(a) for a petitioner to simply allege that he or she has been "harassed or intimidated” by the respondent.
In this case Bachowski alleged in his petition that he had been constantly harassed by the actions and conduct of Salamone. The alleged harassing acts specifically identified in the petition were that Sala-mone made false charges against him to the local police department and physically damaged his property. These specifically identified acts constitute the type of "facts” which must be alleged under sec. 813.125(5)(a), Stats. Accordingly, the notice provided was sufficient.
2) THE PROOF AT THE HEARING
At the hearing on the injunction, no evidence concerning property damage or false charges was offered. The testimony of Mrs. Bachowski and neighbors largely concerned Salamone’s yelling at the Bachowskis. The judge stated at the hearing that Salamone’s yelling across the street constituted harassment. There was no proof and there were no findings concerning the acts and conduct specified in Bachowski’s petition — false charges and property damage. Given the disparity between what was alleged in the petition and what was offered and proven *414at trial, we conclude that the proof in this case was insufficient as a matter of law.
3) THE INJUNCTION
The violation of an injunction issued under sec. 813.125, Stats., is a criminal offense. Substantial fines and imprisonment could result. Section 813.125(7). Accordingly, injunctions issued under this section must be specific as to the acts and conduct which are enjoined.
We conclude that the injunction issued in this case does not meet these standards. The judge restrained Salamone from "harassing petitioner, having any contact with petitioner or coming upon petitioner’s premises.” The enjoined conduct is described too broadly. The statute contemplates that the court will ultimately determine whether acts which allegedly harass a person do in fact constitute harassment under the statute. See sec. 813.124(4)(a)3, Stats. Only the acts or conduct which are proven at trial and form the basis of the judge’s finding of harassment or substantially similar conduct should be enjoined.
In this case the judge concluded that Salamone’s repeated yelling at Bachowski constituted harassment. The judge’s order enjoins Salamone from "harassing” Bachowski or having "any contact” with him. This language, unfortunately, could proscribe conduct which is constitutionally protected, e.g., distributing campaign literature, or which simply would not constitute harassment under the statute, e.g., saying good morning to Mr. Bachowski or his family. Thus, we conclude the injunction is drafted too broadly and is therefore invalid.
In summary, we conclude that the statute is constitutional with respect to the notice required by *415due process. The statute is neither vague nor over-broad. However, because the statute was improperly applied, we reverse the decision of the court of appeals.
By the Court. — The decision of the court of appeals is reversed.
"947.013 Harassment. (1) Whoever, with intent to harass or intimidate another person, does any of the following is subject to a Class B forfeiture:
"(a) Strikes, shoves, kicks or otherwise subjects the person to physical contact or attempts or threatens to do the same.
"(b) Engages in a course of conduct or repeatedly commits acts which harass or intimidate the person and which serve no legitimate purpose.”
"813.125 HARASSMENT RESTRAINING ORDERS AND INJUNCTIONS. (1) Definition. In this section, 'harassment’ means any of the following:
"(a) Striking, shoving, kicking or otherwise subjecting another person to physical contact or attempting or threatening to do the same.
"(b) Engaging in a course of conduct or repeatedly committing acts which harass or intimidate another person and which serve no legitimate purpose.
"(2) Commencement of action. An action under this section may be commenced by filing a petition described under sub. (5)(a). No action under this section may be commenced by service of summons. Section 813.06 does not apply to an action under this section.
"(3) Temporary restraining order, (a) A judge may issue a temporary restraining order ordering the respondents to cease or avoid the harassment of another person, if all of the following occur:
"1. The petitioner files a petition alleging the elements set forth under sub. (5)(a).
"2. The judge finds reasonable grounds to believe that the respondent has violated sec. 947.013.
"(b) Notice need not be given to the respondent before issuing a temporary restraining order under this subsection. A temporary restraining order may be entered only against the respondent named in the petition.
"(c) The temporary restraining order is in effect until a hearing is held on issuance of an injunction under sub. (4). A judge shall hold a hearing on issuance of an injunction within 7 days after the temporary restraining order is issued, unless the time is extended upon the written consent of the parties or extended once for 7 days upon a finding that the respondent has not been served with a copy of the temporary restraining order although the petitioner has exercised due diligence.
"(4) Injunction, (a) A judge may grant an injunction ordering the respondent to cease or avoid the harassment of another person, if all of the following occur:
"1. The petitioner has filed a petition alleging the elements set forth under sub. (5)(a).
*402"2. The petitioner serves upon the respondent a copy of a restraining order obtained under sub. (3) and notice of the time for the hearing on the issuance of the injunction under sub. (3)(c).
“3. After hearing, the judge finds reasonable grounds to believe that the respondent has violated sec. 947.013.
"(b) The injunction may be entered only against the respondent named in the petition.
"(c) An injunction under this subsection is effective according to its terms, but for not more than 2 years.
"(5) Petition, (a) The petition shall allege facts sufficient to show the following:
"1. The name of the person who is the alleged victim.
"2. The name of the respondent.
"3. That the respondent has violated sec. 947.013.
“(b) The clerk of circuit court shall provide simplified forms.
"(6) Arrest. A law enforcement officer shall arrest and take a person into custody if all of the following occur:
"(a) A person named in a petition under sub. (5) presents the law enforcement officer with a copy of a court order issued under sub. (3) or (4), or the law enforcement officer determines that such an order exists through communication with appropriate authorities.
"(b) The law enforcement officer has probable cause to believe that the person has violated the court order issued under sub. (3) or (4).
" (7) Penalty. Whoever violates a temporary restraining order or injunction issued under this section shall be fined not more than $1,000 or imprisoned not more than 90 days or both."