The respondent is asked to indicate a preference between two equally popular interests rather than simply “like” or “dislike.” While a “like-dislike” format has the appeal of simplicity, accumulating research has indicated that this type of format is prone to systematic bias.
Perhaps the most unique feature of the JVIS is its method of scale construction. Each scale was designed to measure the interest designated by the scale name and to be relatively unrelated to other scales. To accomplish this result, careful attention was paid to the preparation of a large pool of activities. The ultimate quality and validity of a vocational interest survey rests on the fidelity to which its constituent activities reflect the interest or interests in question. In the case of the JVIS, extraordinary measures were introduced to foster careful item development and selection. This was followed by administration of these items to large samples of males and females, well over a thousand of each. Final activity selection involved a series of multivariate psychometrically-based procedures designed to select activities most clearly related to the interests being assessed, to suppress response biases, and to minimize the redundancy between scales. From the initial activity pool of well over 3,000 items, the very best have been retained for use in the published JVIS.
A notable feature of JVIS scale construction relates to the choice of format for the test booklet. The respondent is asked to indicate a preference between two equally popular interests rather than simply “like” or “dislike.” While a “like-dislike” format has the appeal of simplicity, accumulating research has indicated that this type of format is prone to systematic bias. Individuals may show a general disposition to respond “like” or “dislike” rather than express their preference for the activity described. This results in systematic error (accounting for as much as a third of the total variance) and poor discrimination between vocational interest scales. The use of the forced-choice activity pairing procedure on the JVIS completely eliminates this source of response bias.
Another feature of the JVIS is that it places equal emphasis upon the measurement of interests of women and men. The Survey was standardized in such a way that an equal number of males and females contributed to the selection of activities and scales, and that activities were required to show discrimination for each sex separately. The format allows males and females to be measured in terms of a common set of interest dimensions which do not make discriminations on the basis of traditional “male” and “female” occupations
Frequently Asked Questions
The JVIS is a complex and detailed instrument, so it’s natural that you might have some questions about it. Listed below are the most frequently asked questions.
What does the JVIS report tell me?
Your JVIS profile describes areas of career activity in which you have indicated a high interest. Your scores are compared with those of a variety of students and with people in different job groups. Your JVIS Extended Report and the Career Exploration Guide may be used, together with other information about your interests and abilities, in making educational and career decisions.
Will the results of the JVIS tell me whether or not I will succeed at a particular job?
The JVIS measures interests, not abilities. A high score on a scale or similarity to a job group indicates that you will probably be more satisfied working in that area. Whether or not you will be successful is another matter, depending on your skills, motivation, and opportunities.
Is this career interest report 100% accurate?
The JVIS was developed using the best and most modern procedures available. This report has also been very carefully designed to help you better understand your career interests, and you may have confidence in your results. However, no career interest survey is 100% accurate. Your interests may change somewhat from time to time. You should also consider other things in addition to interests in planning your education and career.
Why are there so many questions?
Accuracy is important if people use information from an inventory to help make decisions. In order to enhance the accuracy of your career interest assessment, the JVIS uses many questions of high psychometric (measurement) quality. This makes the assessment more trustworthy. Each Basic Interest Scale contains 17 activities. There are 34 Basic Interest Scales in the JVIS. Therefore, the total number of activities you would need to rate, if you were to answer each one individually, is 17 X 34 = 578. The unique forced-choice format employed by the JVIS means that you get a highly reliable assessment having responded to only half as many questions!
Sometimes I don’t like either option but have to choose one, sometimes I like both and can only choose one. Does this pose a problem for my results?
This is a common concern, but the JVIS looks at patterns of responses over many pairs of activities. How you respond to one particular question is not of as much interest as your overall pattern of results. However, it is important to choose carefully which activity you like most (or dislike least) from each pair. Although the JVIS is interested in your overall pattern of responses, the overall pattern is only as good as the individual responses. Responding carefully will help you get a more accurate assessment of your own interests.
Why compare my answers to those of other people?
By comparing your answers to those of other people, the JVIS assesses your relative levels of interest in different areas. Much like a score on a test in school it is often interesting to know how others performed on the same test. If you scored 7 out of 10 on a test, it is clear that you answered 70% of the questions correctly. Whether you consider this to be good or bad will depend partly on your own score (70%), but information about how others performed is also relevant. If you also learned that most people scored between 40% and 50% on the same test, you might interpret your own score differently than if you found out that most other people answered all questions correctly. The JVIS builds in information about how other people respond to help you interpret areas in which you tend to be more or less interested than others.
With whom can I discuss these results?
If possible, you should discuss these results and your plans and aspirations with a career counselor, whose professional training and experience with career interest surveys and with the world of work may be helpful. Also, your counselor can tell you where to get additional educational and career information. You can find career counselors (or advisors) in most schools, colleges, and universities. In addition, some work in private practice or in local employment centers.
My Similarity to Job Groups does not seem to match my Basic Interest scale scores. Why is this?
It is possible to obtain a high Basic Interest scale score on a particular scale like Law, and not have a high score on the associated Job Group (e.g., Occupations in Law and Politics). This does not necessarily mean that these sources are providing conflicting information, or that one or both are incorrect. Rather, they are providing different information. Raw scores on the Basic Interest scales reflect the number of times that you have chosen activities associated with a particular occupation or activity. Percentiles give information about how your raw score on that scale compares to scores of other people. On the other hand, the Similarity to Job Groups represents the overall similarity of all 34 Basic Interest dimensions of your profile to those for persons working in various occupations. For example, lawyers usually obtain high scores on the Basic Interest scale for Law. They also usually show high scale scores on Technical Writing, Business, and Finance. If someone happened to obtain a high score on Law, but lower scores for the other three scales, this would result in a lower degree of similarity to the Occupations in Law and Politics Job Group.
My JVIS Basic Interest profile is not similar to any Job Group! What does this mean?
If, on your report, your similarity to all (or most) Job Groups is “neutral,” it could mean that you do not have a well developed and consistent interest pattern at the present time. Further exploration and experience in a variety of areas will help you find those things that interest you, and those that don’t. You may want to explore career areas very widely. One strategy is to gather information about one or two jobs relevant to each of the 32 Job Groups. After you’ve gathered more information and gained experience in various areas you may wish to retake the JVIS.
Psychometric Properties
The JVIS is one of the most carefully and elaborately constructed psychological instruments ever published. The most modern methods of test and scale construction, and the latest theoretical developments relating to the psychology of work have been incorporated with the aim of providing a comprehensive, accurate, and sex-fair assessment of vocational interests.
The Jackson Vocational Interest Survey (JVIS) is the product of years of careful research. Information about this research, as well as more details about the psychometric properties of the JVIS can be found in the JVIS Manual, available from SIGMA Assessment Systems. A brief version of this manual, the JVIS Quick Manual, is also available for download.
Scale Construction
Definition of the JVIS scales was based on a reconceptualization of occupational preferences in terms of work roles and work styles. Work roles refer to relatively homogeneous sets of activities relevant to occupations. A work role may strongly relate to certain occupations such as scales for Medical Service or Law, or cut across particular occupations and be relevant to a variety of careers, as in the case of Supervision or Human Relations Management. Work styles refer to a preference for certain kinds of work environments. For example, computer programmers and physical scientists are often required to work long hours to find solutions to difficult problems. Their scores on the Stamina scale are consistently high.
Another feature of the JVIS is that it places equal emphasis upon the measurement of interests of women and men. The JVIS was standardized in such a way that an equal number of males and females contributed to the selection of items and scales, and that items were required to show discrimination for each sex separately. The format allows males and females to be measured in terms of a common set of interest dimensions which do not make discriminations on the basis of traditional “male” and “female” occupations. Counselors who wish to give individuals an equal opportunity to consider occupations traditionally associated with only one sex can do so by employing the JVIS.
Perhaps the most unique feature of the JVIS is its method of scale construction. Each scale was designed to measure the interest designated by the scale name and to be relatively unrelated to other scales. To accomplish this result, careful attention was paid to the preparation of a large pool of items reflecting basic work role and work style dimensions. This was followed by administration of these items to large samples of males and females, well over a thousand of each. Final item selection involved a series of multivariate psychometrically-based procedures designed to select items most clearly related to the interests being assessed, to suppress response biases, and to minimize the redundancy between scales.
Norms
The most recent normative sample of JVIS profiles was collected in 1999. These consist of the responses of 1750 males and 1750 females from Canada and the U.S. This sample of 3500 individuals includes the responses of 2380 secondary school students (1190 males and 1190 females) and 1120 adults (560 males and 560 females). The adult sample consists of university and college students as well as adults seeking career interest assessment.
Reliability of JVIS Basic Interest Scales
The JVIS manual presents test-retest coefficients for two distinct samples. The first sample is a group of 172 university students who completed the JVIS one week apart, as part of introductory psychology research participation requirements. These test-retest reliability’s range from .91 for Social Service to .72 for Independence, with a median of .84. The second sample is from a study by Berk (1988) assessing dimensions of person reliability in the context of vocational assessment. A group of 95 first year university students, 43 men and 52 women, completed the JVIS on two occasions separated by four to six weeks. Test-retest reliability’s range from .92 for Social Service to .69 for Independence and Academic Achievement, with a median of .82. Internal consistency coefficients for JVIS Basic Interest scales are also presented in Table 4-2. Coefficients in the third column are based on a sample of 1573 high school students, 799 males and 774 females, who were administered the JVIS during school hours. These values range from .70 to .91, with a median of .81. Listed in the fourth column of Table 4-2 are reliability coefficients (coefficients alpha) for the normative sample of 1750 males and 1750 females. Coefficient alpha values range from .88 for Mathematics and Medical Services to .54 for Professional Advising with a median of .72. Lower values are indicative of scales assessing a number of facets.
Reliability of JVIS General Occupational Theme Scales
Internal consistency reliability’s for the 10 General Occupational Themes based on the normative sample have a median value of .875. The test-retest reliability’s from two respondent samples have a respective median values of .885 and .895.
Reliability of Individual JVIS Profiles
Reliability has traditionally been employed to describe tests or scales, not individuals. But in counseling decisions the question of the reliability of a single individual’s responses is just as much a matter of concern as is the question of the reliability of the test being completed. Accordingly, a method was devised (Jackson, 1976) for appraising individual reliability that has been incorporated into computer scoring. This score appears in the Administrative Indices section of each report as the Response Consistency Index. It is simply an odd-even reliability computed on a single individual across many scales, rather than the more usual odd-even reliability coefficient calculated on a single scale across many individuals. Thus, items in each scale were ranked in order and numbered sequentially. The total scores received by an individual for the odd-numbered items on each of the 34 scales were assigned to the x variable and the total score received for the even-numbered items to the y variable. A product moment correlation (R) is then calculated across the 34 scales and corrected by the Spearman-Brown formula. Berk and Fekken (1990) administered the JVIS to a sample of 95 university students on two occasions separated by four to six weeks. The mean reliability of individual profiles (corrected by the Spearman-Brown formula) was .84 on the first occasion and .87 on the retest occasion. The theoretical expected value of purely random responding, confirmed by Monte Carlo studies, is 0.00, with a standard deviation of about .18. Given the distributions of real and of random individual reliability coefficients, one can reasonably assume that individuals on whom a value of less than .20 is obtained can be categorized as probably primarily attributable to careless, non-purposeful, and/or unarticulated responding. The higher the individual R coefficient, the more confidence one can have in the reliability of the profile.