The controlling question here is whether an employer’s retirement plan is subject to the Iowa Civil Rights Act, Chapter 601A, The Code 1973, in particular the age discrimination provisions of section 601A.7 (1)(a), when a sixty-five-year old employee, who chose not to participate in the financial benefit portion of the plan, is terminated pursuant to the plan.1 The Iowa Civil Rights Commission found discrimination. On judicial review, the district court reversed the Commission. We affirm the district court.
Petitioner Loras College, the employer, is a private co-educational liberal arts institution located in Dubuque. It is funded, sponsored and partially sustained by the Roman Catholic Archdiocese of Dubuque. The college employs as faculty both priests and lay persons.
Respondent Iowa Civil Rights Commission is a state agency established under Chapter 601A, to, inter alia, “receive, investigate, and pass upon the merits of complaints alleging unfair or discriminatory practices.” § 601A.5(2), The Code 1973.
Upon the complaint properly filed with the Commission by Dr. Edward J. Schuster, the employee, the Commission found that Loras discriminated against him because of his age in ending his employment as a teacher.
I. Background and proceedings. Dr. Schuster, a layman, was born March 25, 1908. He joined the Loras faculty in 1956 as an associate professor of modern foreign languages. He later was awarded tenured status as a full professor, teaching Spanish and German. Under Loras’ policy, tenure ends at age sixty-five. This allows for the hiring of younger teachers, for the constant and methodical regeneration of a qualified faculty, for the incorporation of new ideas and theories of education, and for maintaining the quality of education at Loras. See DeShon v. Bettendorf Community School District, 284 N.W.2d 329, 333 (Iowa 1979). Dr. Schuster became sixty-five during the 1972-73 academic year. He taught until May 13,1973, when he was retired by Loras on the basis of his age.
Effective September 1, 1960, Loras had established a comprehensive retirement plan for lay persons, who were faculty members, administrative personnel and key supervisory maintenance employees. The plan included a document entitled “Retirement Plan” (hereinafter referred to as “benefit program”), in which the policy of retiring all benefit participants at the normal retirement age of sixty-five was set forth. Under the terms of the benefit program each participant in the program would contribute five percent of his basic salary through payroll deductions by Loras. The college would add equal amounts as its contribution and apply the combined sum to the purchase of retirement benefits for the employee. The benefit program was voluntary for such covered employees then serving and was compulsory for future employees in the covered categories.
As part of the retirement plan, Loras and its faculty established a policy that lay faculty members were to retire at the end of the academic year in which they attain the age of sixty-five. The policy was set forth *145in the document on Contractual Relations and Status of Faculty Members, as well as being an integral part of the document entitled “Retirement Plan” or benefit program. Dr. Schuster knew of the retirement policy and the benefit program Loras had established.
Although he clearly had the opportunity to participate in the benefit program of the retirement plan, Dr. Schuster chose not to participate. Therefore, the five percent employee contributions were not deducted from his salary from 1960 until his retirement in 1973.
The last signed contract between Loras and Dr. Schuster only provided employment for him for the 1972-73 academic year, in accordance with college policy and pursuant to the overall retirement plan.
The Commission found as a fact that the Loras benefit program as it was applied to its participants was not a subterfuge to evade the operation of the Iowa Civil Rights Act. § 601A.15, The Code 1973.
Loras suffered a significant decline in overall student enrollment commencing in 1971. The college also adopted a new curriculum, which went into effect in the fall of 1971, through which the graduation requirement of fourteen semester hours of foreign language was eliminated. These events led to a severe decline in the number of students taking language courses, with the resultant decrease in the need for faculty members teaching in the modern foreign language department.
A teacher in the foreign language department was expected to teach 270 student credit hours per year prior to 1972. In the fall of 1972 the number of teaching hours for each faculty member had fallen to seventy-five per year. Additionally, Loras had suffered significant financial losses during the five-year period from 1968 to 1972.
In 1972 and 1973 Loras found it necessary that the number of faculty be reduced in the department of modern foreign languages, and in 1973 the necessary reductions were determined to be mandatory.
The department was to be reduced from five to three teachers. The question as to who should be terminated had to be answered.
Recognizing the retirement policy of Lo-ras, Dr. Schuster, on December 9, 1972, applied in writing to the Faculty Council for an extension of his service beyond the retirement age of sixty-five.
The Faculty Senate and Faculty Council at Loras studied the matter of faculty staffing and made general recommendations to the president of Loras. All faculty members in the department of modern foreign languages were considered before the president of Loras made his decision to apply the retirement plan’s policy of retirement to Dr. Schuster and thereby denied his request for an extension of service. In addition to Dr. Schuster, another faculty member, Dr. Prendergast, was also retired in 1973 in accordance with the same retirement plan. No teaching faculty members have been added to the department since the retirement of Drs. Schuster and Pren-dergast.
After his termination, Dr. Schuster sought comparable teaching positions. He was unable to find such employment for the 1973-74 school year. He did obtain a position at Northern Arizona University (NAU) for 1974^75, but at a lower salary. He remained with NAU until the end of the 1976-77 academic year, at which time he refused a similar appointment for the next year.
On August 1, 1973, Dr. Schuster filed a complaint with the Civil Rights Commission, charging age discrimination against him by Loras. On April 13, 1978, after an evidentiary hearing before a hearing officer, the Commission found in favor of Dr. Schuster, ordered Loras to reinstate him and awarded certain monetary damages.
Loras petitioned for judicial review in district court under section 17A.19, The Code 1977.2 The court ruled, among other *146things, that section 601A.15, The Code 1973, exempted Loras from the provisions of the Iowa Civil Rights Act, and the discrimination complaint was dismissed. The Commission appealed under section 17A.20, The Code 1977.
Because we find section 601A.15, The Code 1973, dispositive of this appeal, we discuss only the effect of that statute under this record and do not consider the other issues raised by Loras and the Commission.
Unless otherwise stated, all later references will be to the 1973 Code, which was in effect when the alleged discrimination occurred.
In view of the manner in which the parties proceeded on judicial review, this was a contested case before the Commission within the meaning of section 17A.2(2), The Code 1977. Our review under section 17A.20 is not de novo. We “review the record in the manner specified in § 17A.19(7) and make anew the judicial determinations specified in § 17A.19(8).” Hoffman v. Iowa Department of Transportation, 257 N.W.2d 22, 25 (Iowa 1977); see Jackson County Public Hospital v. Public Employment Relations Board, 280 N.W. 426, 429 (Iowa 1979) (quoting Hoffman). “Our review is limited, as the district court’s review should have been, to the record made before the hearing officer.” Davenport Community School District v. Iowa Civil Rights Commission, 277 N.W.2d 907, 909 (Iowa 1979); Hoffman, 257 N.W.2d at 25.
II. Exception of the Loras retirement plan from Chapter 601A.
A. Contentions of the parties. The Lo-ras retirement plan was effective in 1960. The Iowa Civil Rights Act became effective in 1965. 1965 Iowa Acts, ch. 121. The Act was amended in 1972 to include coverage of age discrimination. 1972 Iowa Acts, ch. 1032.
Under the Iowa Civil Rights Act it is an unfair or discriminatory practice, in violation of section 601A.7(1)(a), for a person 3 to discharge any employee because of the age of such employee, unless such action is based on the nature of the occupation.
Section 601A.15 provides an exception to this general rule. “The provisions of this chapter relating to discrimination because of . age shall not be construed to apply to any retirement plan or benefit system of any employer unless such plan or system is a mere subterfuge adopted for the purpose of evading the provisions of this chapter.” § 601A.15 (emphasis added).
There is no question here as to whether Loras had a “retirement plan or benefit system” within the meaning of section 601A.15. Both parties agree that such a plan existed; however, they do not agree as to whether the college’s policy of retirement at age sixty-five, as applicable to Dr. Schus-ter, was part of the plan. The parties also agree that the plan, as it applied to those individuals electing to participate in the benefits therefrom, was not a mere subterfuge adopted for the purpose of evading the provisions of the Act.
The Commission concedes in its brief that the section 601A.15 exception makes involuntary retirement because of age legal, where such retirement is undertaken pursuant to a “retirement plan or benefit system.” The Commission claims, however, that the exception does not apply to a “retirement plan or benefit system” unless such plan or system provides income or pension after retirement to the specific retiree being terminated by the employer; and, therefore, the Loras plan is irrelevant to Dr. Schuster.
The Commission further concedes that if Dr. Schuster had participated in the Loras College benefit program, section 601A.15 *147would clearly exempt Loras from the application of Chapter 601A.
Loras asserts, relative to Dr. Schuster, that because section 601A.15 excepts “any retirement plan or benefit system” from the discrimination provisions of chapter 601A when the plan is bona fide and not a mere subterfuge, an employee may be retired at age sixty-five when: the benefit program provides for mandatory retirement at age sixty-five; the employee is aware of the overall plan and its retirement provisions; the benefits from the plan are available to the employee at his option; the terms of the employee’s contract provide for one academic year of employment non-renewable at the option of either party; and the overall plan includes the employer’s policy to retire all faculty members at age sixty-five.
Both parties cite a number of federal cases interpreting 29 U.S.C. § 6234 of the federal Age Discrimination in Employment Act of 1967 in support of their various positions. The Commission cites the case of Hodgson v. American Hardware Mutual Insurance Co., 329 F.Supp. 225 (D.C.Minn.1971) (person electing not to participate in a benefit plan could not be involuntarily retired before age sixty-five pursuant to the plan). However, it is significant to note that the Hodgson case was interpreting the federal statute that exempts a “bona fide employee benefit plan,” whereas our Iowa statute exempts “any retirement plan.” Section 601A.15 (emphasis added); 29 U.S.C. § 623(f)(2) (1970). Thus, that federal district court was interpreting a federal statute that differed significantly from the exemption provisions of Iowa’s Act. As we said in Franklin Manufacturing Company v. Iowa Civil Rights Commission, 270 N.W.2d 829, 831 (Iowa 1978), we are not bound by federal cases construing a federal statute when we are called upon to construe our own Civil Rights Act. We decline to follow Hodgson and the other federal cases cited by the parties.
We first consider the purposes of the Iowa Civil Rights Act and the “retirement plan” exception thereto. We will then consider: what is a retirement plan under section 601A.15; what constituted the Loras retirement plan; whether it applied to Dr. Schuster; and whether Loras violated section 601A.7(1)(a) when it retired him.
B. The purposes of Chapter 601A and the exception of section 601A.15. Our task is to determine the meaning of the language in section 601A.15 as it relates to chapter 601A. “Interpretation of a statute is a question of law which must be determined by the judiciary.” West Des Moines Education Association v. Public Employment Relations Board, 266 N.W.2d 118, 124 (Iowa 1978); see Iowa State Department of Health v. Hertko, 282 N.W.2d 744, 749 (Iowa 1979) (citing West Des Moines Education Association). We do not purport to pass on the wisdom of mandatory retirement at a particular age.
“[T]he polestar of all statutory construction [is the] search for the true intention of the legislature.” Iowa National Industrial Loan Co. v. Iowa State Department of Revenue, 224 N.W.2d 437, 439 (Iowa 1974). While this rule should be used to the exclusion of all other rules of statutory construction, the other rules must be applied together in light of the particular facts of each case when used to help us find the true legislative intent. Id.
We now set forth the general rules of statutory construction considered in this case.
(1) In considering legislative enactments we should avoid strained, impractical or absurd results.
(2) Ordinarily, the usual and ordinary meaning is to be given the language used but the manifest intent of the legislature will prevail over the literal import of the words used.
*148(3) Where language is clear and plain, there is no room for construction.
(4) We should look to the object to be accomplished and the evils and mischiefs sought to be remedied in reaching a reasonable or liberal construction which will best effect its purpose rather than one which will defeat it.
(5) All parts of the enactment should be considered together and undue importance should not be given to any single or isolated portion.
(6) We give weight to the administrative interpretation of statutes, particularly when they are of longstanding.
Id. at 440 (citations omitted).
In Franklin Manufacturing Company we had the opportunity to interpret section 601A.12, The Code 1977, which is identical to section 601A.15, The Code 1973. The question before us in that case was “whether [section 601A.12] exempts all benefit systems or only those relating to retirement.” 270 N.W.2d at 831. We held that the legislature intended to exempt, under section 601A.12, “only those plans or benefit systems relating to retirement.” Id. at 832.
While the Act does not contain a separate section declaring the legislative purpose and policy behind the Act, it is obvious from the clear and plain language of the statute itself that its primary purpose, in the context of this case, is to prevent age discrimination in hiring and discharging workers. See § 601A.7.
The legislature, within its broad discretion, has seen fit to provide an exception to the discrimination provisions of Chapter 601A when an employer hires or discharges employees because of age, where the employer does so pursuant to “any retirement plan or benefit system [that is not] a mere subterfuge adopted for the purpose of evading the provisions of [the Act].” § 601A.15.
The exception protects the employer’s right to require the involuntary retirement of employees on the basis of their age, but only when the employer does so pursuant to a “retirement plan or benefit system” within the meaning of section 601A.15.
It is important to note that, without this exception, an employer would never be permitted under the Act to retire an employee because of his age, unless such retirement is based upon the nature of the occupation. The Iowa Act (unlike its federal counterpart, 29 U.S.C. § 623 et seq., which allows discrimination on the basis of age, unless the individual is between ages forty and seventy) has no limiting age category to which it applies. The Iowa Civil Rights Act applies across the board with respect to individuals of all ages.
A recent amendment to section 601A.13, The Code 1979, which was the same as section 601A.15, The Code 1973, provides additional support for the proposition that the exception allows involuntary retirement pursuant to a bona fide “retirement plan or benefit system.” The amendment provides: “However, a retirement plan or benefit system shall not require the involuntary retirement of a person under the age of seventy because of that person’s age.” § 601A.13, The Code 1979, as amended by 1979 Session, 68th G.A., ch. 35, § 10. By implication, the exception statute in effect when Dr. Schus-ter was terminated in 1973, with which we concern ourselves today, permitted the involuntary retirement of employees even though they were under the age of seventy, if such termination was pursuant to a bona fide “retirement plan or benefit system.”
Beyond the general policy of favoring the involuntary retirement of employees when done pursuant to section 601A.15, the Act does not provide any specific guidance as to what is meant by “any retirement plan or benefit system” as that phrase is used in section 601A.15. Even if we discern that the legislature was attempting to favor retirement plans and benefit systems that compensate employees over those that merely discharge an employee without compensation, the question still remains as to what constitutes “any retirement plan or benefit system” within the meaning of section 601A.15.
C. Retirement plan under section 601A.15. We believe a “plan” in the context of section 601A.15 is “an orderly ar*149rangement of parts in terms of an overall design or objective ... a schematic table or program of related parts or items . a detailed and systematic formulation of a large scale campaign or program of action.” Webster’s Third New International Dictionary 1729 (unabridged 1976). The definition of “retirement plan” cannot be limited to the mere document that provides the benefits to the employee, even though such a document constitutes a major portion of the plan.
Not only did Loras provide for the payment of benefits to employees when they retired, but it also had an institutional policy establishing age sixty-five as the retirement age for all individuals in Dr. Schuster’s position. This policy, of which Dr. Schuster had knowledge, must be considered as part of Loras College’s “retirement plan or benefit system” within the meaning of section 601A.15.
The “retirement plan or benefit system” used by Loras clearly applied to Dr. Schus-ter. He was subject to Loras’ policy to retire all faculty members at age sixty-five, and he had the option of participating in the benefit program.
D. Receipt of benefits by retired employees. We next must determine whether section 601A.15 requires the payment of benefits by the employer to an employee before he can be involuntarily retired on the basis of age without violating section 601A.7, where that employee had the free choice to participate or not participate in the provided benefits. The issue, stated in terms of the statutory language, takes us back to the question of whether the “retirement plan or benefit system” employed by Loras College is a “mere subterfuge adopted for the purpose of evading the provisions of this chapter.” § 601A.15.
The Commission found that Loras had in existence a bona fide retirement plan which was not a mere subterfuge to evade the operation of chapter 601A. It is clear, however, from the Commission’s decision, that it only considered the plan bona fide in relation to those employees who elected to participate in the benefits offered through Loras College’s plan.
We believe the opportunity to participate in the benefits of a “retirement plan or benefit system” is all that section 601A.15 requires. A retirement plan is not a “mere subterfuge” when it gives an employee the freedom to choose between participating in the benefits of a “retirement plan or benefit system” established by the employer and receiving presently that portion of his pay check that would normally be applied toward the employer’s plan. It is understandable that an employee would desire the immediate use of his income for some present needs or desires. We do not believe the legislature intended under Chapter 601A to require an employer, who provides his employees with such an option, to retain an employee indefinitely when that employee makes the conscious choice to receive all his earnings presently, as opposed to paying a portion of his earnings towards the employer’s plan and sharing in the future benefits of the program. Where the option to participate in the benefits from the plan is given to the employee, any discernible policy of providing benefits upon the involuntary retirement of an employee is not circumvented. The employee still has the freedom to choose to participate in the benefit portion of the plan.
A contrary construction would lead to an impractical and absurd result.
We hold today that when an employer’s “retirement plan or benefit system” offers an employee the option to participate in the benefits from such a plan and the plan requires the retirement of the employee at a given age, the conscious decision by the employee not to participate in the retirement benefits from the plan does not entitle the employee to be retained beyond the mandatory retirement age established by the plan. Such an option does not render the plan a “mere subterfuge adopted for the purpose of evading the provisions of” the Iowa Civil Rights Act.
Because the Loras retirement plan did apply to Dr. Schuster and the plan came within the exception in section 601A.15, the *150Iowa Civil Rights Act in effect in 1973 did not apply to Loras’ actions under the present record. We affirm the ruling of the district court in that regard.
We also note that Loras adopted its retirement plan in 1960, approximately five years prior to the date upon which the Iowa Civil Rights Act first became law, and approximately twelve years prior to the date age discrimination was made part of the Act. Although we need not hold today that a “retirement plan or benefit system” within the meaning of section 601A.15, adopted prior to the effective date of the Act was per se adopted without the purpose of evading the provisions of the Act, to show an intent in 1960 to evade the purpose of a statutory provision adopted in 1972 attributes, at the minimum, a tremendous amount of foresight to the employer. See United Air Lines v. McMann, 434 U.S. 192, 203, 98 S.Ct. 444, 450, 54 L.Ed.2d 402, 413 (1977).
We do not determine whether a retirement plan, which does not pay benefits, or at least provide the employee with the option to participate in adequate benefits from the employer’s benefit program, properly falls within the section 601 A. 15 exception, nor do we make any additional determination as to the meaning of section 601A.13, The Code 1979, as amended by 1979 Session, 68th G.A., ch. 35, § 10.
AFFIRMED.
All Justices concur except McCORMICK, LeGRAND, ALLBEE and LARSON, JJ., who dissent.. The Code sections relevant to our discussion of this issue are sections 601A.7(l)(a) and .15, The Code 1973.
Section 601A.7 provides:
1. It shall be an unfair or discriminatory practice for any:
a. Person to refuse to hire, accept, register, classify or refer for employment, to discharge any employee, or to otherwise discriminate in employment against any applicant for employment or any employee because of the age, race, creed, color, sex, national origin, religion or disability of such applicant or employee, unless based upon the nature of the occupation. .
(Emphasis added).
Section 601A.15 provides:
The provisions of this chapter relating to discrimination because of sex or age shall not be construed to apply to any retirement plan or benefit system of any employer unless such plan or system is a mere subterfuge adopted for the purpose of evading the provisions of this chapter.
(Emphasis added).
. Because the parties followed chapter 17A, The Code 1977, for judicial review in district court of the Commission’s decision, our review of that judgment is under section 17A.20. *146Therefore, we pass the question of whether sections 601A.10(6)-(7). The Code 1973, should have been utilized for review of the Commission’s ruling in the district court.
. Loras College is a person under the definition in Section 601A.2(2), which provides:
2. “Person” means one or more individuals, partnerships, associations, corporations, legal representatives, trustees, receivers, and the state of Iowa and all political subdivisions and agencies thereof.
. 29 U.S.C. § 623(f) (1970), provided in part:
It shall not be unlawful for an employer . to observe the terms of a bona fide seniority system or any bona fide employee benefit plan such as a retirement, pension, or insurance plan, which is not a subterfuge to evade the purposes of this [Act], except that no such employee benefit plan shall excuse the failure to hire any individual .