StrengthsFinder is an online personal assessment test designed to outline the user's strengths. It is described in Now, Discover Your Strengths, a self-help book written by Marcus Buckingham and Donald O. Clifton that was first published in 2001. The authors advocate focusing on building strengths rather than focusing on weaknesses.
The theory behind StrengthsFinder is that each adult individual possesses a certain number of fixed universal personal-character attributes, defined by the authors as "talent themes," which, together, result in an individual's tendency to develop certain skills more easily and excel in certain fields in a sustainable way while failing or not being able to sustain success or high levels of effectiveness in other fields.
The authors claim that by identifying the individual strength of the members of the organization, its members can be utilized in more suiting positions, hence developing the required skills easily, helping to reduce turnover, improve employee morale and the organization's overall performance.
The Gallup Organization claims to have distilled the theory into practice by interviewing 1.7 million professionals from varying fields.  Having quantified the different traits of the people they interviewed, they came up with 34 distinct patterns—what they call "talent themes"—that best describe the range of human uniqueness observed during their research: 
- Achiever - one with a constant drive for accomplishing tasks
- Activator - one who acts to start things in motion
- Adaptability - one who is especially adept at accommodating to changes in direction/plan
- Analytical - one who requires data and/or proof to make sense of their circumstances
- Arranger - one who enjoys orchestrating many tasks and variables to a successful outcome
- Belief - one who strives to find some ultimate meaning behind everything they do
- Command - one who steps up to positions of leadership without fear of confrontation
- Communication - one who uses words to inspire action and education
- Competition - one who thrives on comparison and competition to be successful
- Connectedness - one who seeks to unite others through commonality
- Consistency - one who believes in treating everyone the same to avoid unfair advantage
- Context - one who is able to use the past to make better decisions in the present
- Deliberative - one who proceeds with caution, seeking to always have a plan and know all of the details
- Developer - one who sees the untapped potential in others
- Discipline - one who seeks to make sense of the world by imposition of order
- Empathy - one who is especially in tune with the emotions of others
- Focus - one who requires a clear sense of direction to be successful
- Futuristic - one who has a keen sense of using an eye towards the future to drive today's success
- Harmony - one who seeks to avoid conflict and achieve success through consensus
- Ideation - one who is adept at seeing underlying concepts that unite disparate ideas
- Includer - one who instinctively works to include everyone
- Individualization - one who draws upon the uniqueness of individuals to create successful teams
- Input - one who is constantly collecting information or objects for future use
- Intellection - one who enjoys thinking and thought-provoking conversation often for its own sake, and also can data compress complex concepts into simplified models
- Learner - one who must constantly be challenged and learning new things to feel successful
- Maximizer - one who seeks to take people and projects from great to excellent
- Positivity - one who has a knack for bring the light-side to any situation
- Relator - one who is most comfortable with fewer, deeper relationships
- Responsibility - one who, inexplicably, must follow through on commitments
- Restorative - one who thrives on solving difficult problems
- Self-Assurance - one who stays true to their beliefs, judgments and is confident of his/her ability
- Significance - one who seeks to be seen as significant by others
- Strategic - one who is able to see a clear direction through the complexity of a situation
- Woo - one who is able to easily persuade (short for "Winning Others Over")
The Gallup group has developed an online test that they claim will reveal the test-taker's top five themes. The "Clifton Strengths Finder" www.strengthsfinder.com is a web based questionnaire, which based on the answers claims to be able to define individual "Strengths". A single one time access is possible by entering an access code provided with the book.
Now, Discover Your Strengths, correlating to the "Strength Finder 1.0" Web application has been replaced by the Strengths Finder 2.0 book correlating to the "Strengths Finder 2.0" Web application.
A 2009 study comparing StrengthsFinder to the Myers–Briggs Type Indicator found, "All (100%) of those with Communication and Woo as one of their top five strengths were Extravert. This same pattern occurred between Analytical and Significance with Sensing, Analytical with Thinking, and Discipline and Significance with Judging. Traits appearing with strengths 90 to 99% of the time included Extravert with Activator, Feeling with Empathy, and Judging with Consistency. One strength was totally (100%) associated with a mental function (Analytical and Sensing-Thinking); however, several had no association."
Leading personality psychologists[who?] have challenged the value of the "strength-based development" approach. They find the approach faulty from three different perspectives.
- Strengths-only is not viable: They cite research that few have more than five strengths (defined as competencies where one is stronger than other managers) and that those five typically aren't in areas that are aligned with business needs. Just because one has strengths, they argue, doesn't mean that those strengths will allow someone to be effective.
- Strengths can become weaknesses: Research from groups like the Center for Creative Leadership and numerous personality psychologists shows that leadership derailers—behaviors that negatively impact a leader's potential success—can be defined as overdone strengths. For example, attention to detail can become micro-management; ability to influence can become highly political behavior. Continuing to focus on your strengths, they argue, at a certain point will create negative consequences.
- Weaknesses matter: We typically fail because of our weaknesses, not because we haven't focused enough on our strengths, they argue. By ignoring our "dark side" of personality and focusing only on our strengths we are guaranteeing our failure.
- Rath, Tom (2007). StrengthsFinder 2.0. New York: Gallup Press.
- Buckingham, Marcus (2001). Now, Discover Your Strengths. New York: The Free Press.
- Kaiser, Robert (2009). The Perils of Accentuating the Positive. Tulsa, OK: HoganPress. pp. 5–8. ISBN 978-0-9816457-5-9.