Strong Interest Inventory

Evolution & Model

For over 85 years the Strong Interest Inventory® instrument has provided time-tested, research validated insights to help individuals in their search for a rich fulfilling career. With the highly reliable Strong instrument, you can help individuals discover their interests, preferences and personal styles - exactly the information they need to select classes or choose a career they can be passionate about.

The theoretical structure for Strong Interest Inventory® comes from John Holland’s psychology-based codes. Holland’s theory is based on four main assumptions:

1. In our culture, most people can be categorized into six Themes and each person may be characterized by one Theme or some combination.

2. Job environments can be divided into these same six Themes and each environment is dominated by a particular type of person. Thus, the personality types of co-workers, as much as job requirements, establish the working tenor of a given occupation.

3. People search for environments that let them exercise their skills and abilities, express their attitudes and values, take on problems and roles they find stimulating and satisfying, and avoid chores or responsibilities they find distasteful or formidable.

4. Behavior is determined by an interaction between a person’s personality and the characteristics of his or her working environment. Factors such as job performance, satisfaction, and stability are influenced by this interaction.



The Strong Interest Inventory assessment is ideal for a wide range of applications, including the following:

  • Choosing a college major—helps students uncover their career interests and identify which areas of study are appropriate or required for a particular field
  • Career exploration—opens up the world of work to first-time career seekers and those considering career transition by identifying their interests and demonstrating how they relate to various occupations and careers
  • Career development—helps heighten individuals’ self-awareness and provide deeper understanding of individual strengths and blind spots, including work style and risk-taking orientation
  • Employee engagement—helps employees align their interests with areas of responsibility in their job that reflect those interests
  • Reintegration—helps individuals navigate the reintroduction process after a period of disconnection


A comprehensive portfolio of reports is available, including the following:

  • iStartStrong® Report - puts self-discovery into the hands of anyone seeking career direction. Utilizing two of the four Strong Interest Inventory scales, the iStartStrong™ Report serves as the admission pass to the world of career exploration.
  • Strong High School Profile - identifies specific subjects and academic majors that fit participants’ interests and preferences.
  • Strong Profile, College Edition - identifies specific college courses and academic majors that fit participants’ interests and preferences, and offers encouragement to express unique interests and personal style to help make the college experience more personally enriching.
  • Strong Profile and Interpretive Report - a detailed report that allows a professional to explore their interests both professionally and for leisure activities.

Strong / MBTI Career Report – this unique report offers an amalgamation of your interests with your personality preferences, thereby providing a whole host of information to think through while making career decisions or planning developmental activities.

To view sample reports Click here

Reliability and Validity

In 2012, a review was undertaken of the Strong Occupational Scales to ensure that the instrument best reflected changes in the occupational world and our society, and thus maintaining the scientific soundness of the instrument. The updated instrument now includes 260 Occupational Scales, providing clients and career professionals alike with a wide variety of career options to consider and helping users make informed decisions about the future.

The Internal reliability of General Occupational Themes that come from the Holland’s code is 0.9 and test-retest reliability is at 0.9 over 3 to 6 months.


  • Where Do I Go Next? Using Your Strong Results to Manage Your Career—helps individuals work through their Strong results so they can better understand their interests and target their most promising career path
  • Strong Interest Inventory® User’s Guide: Practitioner’s Tool for Understanding, Interpretation, and Use of the Strong Profile and Interpretive Report—offers practical insights on administration and interpretation of the Strong; includes strategies, resources, and tools for efficient, meaningful delivery of assessment results to individuals and groups

Strong Interest Inventory® Manual with Supplement: Research, Development, and Strategies for Interpretation—provides comprehensive guidance for understanding and administering the Strong assessment, and for helping students, career changers, and employees find meaningful direction

Case Studies

River Side County

Riverside County has had difficulty filling many of its positions with top-quality talent. Though many employees are interested in expanding their career while remaining within the county, often the career they think they want and the career they’ll enjoy and excel in are not one in the same. The challenge lies in identifying the optimum career/educational path for each county employee. Learn More…

Finland University

The disadvantaged backgrounds of TRiO students add urgency to the task of identifying the career paths that maximize their likelihood of success. Students, however, often choose majors for reasons unrelated to key factors underlying success, such as interests, preferences, and personal style. Without a genuine interest in their field, students may find it difficult to succeed. Learn more…