Behaviorally Anchored Rating Scales (BARS) – Definition, Structure & Practice

Behaviorally Anchored Rating Scales (BARS) are a structured appraisal instrument that links each performance level to concrete, observable behavioural descriptions. They make personnel assessments more objective, more comparable and less susceptible to unconscious bias. BARS are particularly well suited to structured interviews, assessment centres and performance reviews.

What Are Behaviorally Anchored Rating Scales (BARS)?

Behaviorally Anchored Rating Scales were developed in 1963 by psychologists Patricia Cain Smith and Lorne Kendall and first published in the Journal of Applied Psychology. Their goal was to reduce the subjectivity of traditional performance appraisals – a problem that remains as prevalent in everyday HR practice today as it was then.

With conventional rating scales, assessors choose between abstract categories such as "excellent", "satisfactory" or "poor". What exactly constitutes "excellent" communication skills is left open – and interpreted differently from one assessor to the next. BARS solve this problem: each point on the scale is defined by a behavioural anchor, meaning a concrete, observable description of typical behaviour. Assessors no longer need to interpret – they match observed behaviour against predefined anchor points.

In doing so, BARS increase inter-rater reliability – the degree to which different assessors reach consistent conclusions when evaluating the same candidate or employee. This is not only a hallmark of fair HR practice, but also an important foundation for legally defensible documentation of selection decisions.

Structure and Components: How Does BARS Work?

A behaviorally anchored rating scale consists of two core elements:

1. Competency dimensions: The performance areas to be assessed – for example, communication skills, problem-solving ability, teamwork or customer orientation. These dimensions are defined specifically for each role and are based on a thorough job requirements analysis.

2. Behavioural anchors: For each competency dimension, concrete behavioural examples are formulated and assigned to scale levels. Five levels are typical – ranging from clearly below average to outstanding performance.

Example: BARS Scale for the Competency "Communication Skills"

This example illustrates the key point: the focus is not on a subjective judgement of "good" or "poor", but on concretely observable behaviour. This makes assessments transparent, justifiable and actionable.

Step by Step: How to Develop a BARS Scale

Developing behaviorally anchored rating scales is time-intensive – and this disadvantage should be factored in honestly when deciding whether to use the instrument. For a single competency, several hours of work are typically required; for a complete job profile covering five to eight dimensions, the effort is correspondingly greater. That said, the investment pays off through consistently reliable appraisals over time.

Phase 1: Job Analysis and Defining Dimensions

Start by clarifying which competencies are critical for the role in question. The foundation is a valid job requirements profile, ideally developed in collaboration with line managers and experienced role holders. Five to eight dimensions per role are recommended – more than that makes the appraisal unwieldy.

Phase 2: Collecting Critical Incidents

Interview people who know the role well – both managers and experienced employees: "Describe a situation in which someone performed particularly effectively in this area – and one in which someone clearly fell short." This method draws on the Critical Incident Technique and provides the raw material for the behavioural anchors to follow.

Phase 3: Formulating Behavioural Anchors

The collected incidents are condensed and translated into clear behavioural statements. Importantly, anchors must be observable, specific and unambiguous – not evaluative or interpretive. "Approaches colleagues openly and proactively" is a good anchor; "is a team player" is not.

Phase 4: Retranslation and Validation

A central step in the BARS methodology is retranslation: independent individuals who were not involved in the development process blindly assign the formulated behavioural anchors to the correct competency dimensions. Only anchors that are assigned clearly and consistently are retained in the final instrument. This step safeguards the content validity of the scale.

Phase 5: Calibration and Training

Before BARS go live, all assessors should be trained – ideally using concrete practice scenarios. Calibration sessions, in which everyone rates the same sample behaviour and then discusses the results, significantly increase inter-rater reliability.

Strengths and Limitations of BARS at a Glance

Strengths: Objectivity, Bias Reduction, Legal Defensibility

The greatest advantage of behaviorally anchored rating scales lies in their ability to reduce common appraisal errors and unconscious bias. Classic distortions such as the halo-horns effect – where an overall positive impression colours all individual ratings – are mitigated because each dimension is assessed separately against concrete behavioural descriptions. The same applies to the recency effect (recent events are overweighted) and affinity bias (people who are personally liked are systematically rated more favourably).

Further strengths:

• Legal defensibility: Appraisals are documented in a transparent, traceable manner and can be substantiated if challenged.
• Developmental value: Employees receive clear, behaviour-oriented feedback that offers concrete avenues for improvement.
• Acceptance: Behaviour-based feedback tends to be perceived as fairer by those being assessed than abstract ratings.

Limitations: Development Effort and Role Specificity

BARS are role-specific – a scale developed for inside sales cannot simply be transferred to a management position. This makes them demanding to develop and maintain. Organisations should also plan for the fact that anchors will need to be revised when role requirements change – for instance, due to digitalisation or restructuring.

It is also worth noting that BARS do not replace assessor training: the instrument reduces bias, but does not eliminate it entirely. Regular calibration sessions remain important even after implementation.

BARS in Practice: Assessment Centres and Structured Interviews

Behaviorally anchored rating scales deliver their greatest value in two settings in particular:

In the assessment centre, multiple assessors observe candidates completing simulated tasks and exercises. Without a shared evaluation framework, these multi-perspective judgements quickly become inconsistent. BARS provide a common standard that significantly improves the comparability of results.

In the structured interview – for example, when using behaviour-based questions following the STAR method (Situation, Task, Action, Result) – BARS allow immediate, consistent classification of responses. Assessors do not have to rely on gut feeling, but can orient themselves against clearly defined anchor points.

Behaviour-based appraisal methods are, however, only one component of modern, objective personnel selection. Increasingly, organisations complement them with scientifically validated online assessments that capture potential and competencies independently of interview situations. As a scientific spin-off of Freie Universität Berlin, the Aivy platform enables exactly this kind of competency-based diagnostics, structurally reducing assessor bias. Companies such as Lufthansa achieve a hit rate of 96% compared to traditional in-house assessments when combining structured behavioural observation with objective diagnostics – while simultaneously reaching 81% satisfaction among applicants. Further details are available in the Lufthansa success story.

Frequently Asked Questions About BARS

What is the difference between BARS and conventional rating scales?

Conventional scales use numerical values (1–5) or abstract adjectives such as "excellent" to "poor", without defining what those ratings mean in substance. BARS define each level through a concrete behavioural description. This increases inter-rater reliability because all assessors are oriented to the same standard – not to their own personal notion of "good".

How many levels should a BARS scale have?

Five-level scales are the most common and have proven to be practical in everyday use. Seven- or nine-level scales allow finer differentiation, but are harder to calibrate and increase the development effort. For most HR contexts, a five-level scale is sufficiently precise.

How long does it take to develop a BARS scale?

This is the method's main drawback: for a single competency dimension, including the expert group, retranslation and calibration, three to eight hours are typically required. A complete job profile with five to eight dimensions can take several days. This effort amortises over long-term use, but should be factored in realistically when making the decision to proceed.

Can I use BARS in structured interviews?

Yes – and this is in fact one of the most common applications. When behaviour-based interview questions ask candidates to describe specific situations from their past experience (STAR method), BARS enable immediate and consistent classification of responses. Assessors match what has been described against the behavioural anchors, rather than evaluating from instinct. This also strengthens the legal defensibility of selection decisions.

What is the difference between BARS and BOS?

Both instruments are based on concrete behavioural descriptions but differ in their assessment logic. With BARS, assessors select the anchor point that best describes the observed behaviour. With BOS (Behavioral Observation Scales), assessors indicate how frequently a particular behaviour is displayed – for instance on a scale from "almost never" to "almost always". BOS are often easier to develop; BARS are more precise when qualitative performance distinctions are required.

How does BARS reduce unconscious bias?

BARS operate on several levels. The halo-horns effect is mitigated because each competency dimension is assessed separately – a positive overall impression does not automatically colour all individual ratings. The primacy and recency effects (first and last impressions dominate) are reduced because assessors orient themselves against behaviour-based anchors rather than recollective impressions. For a broader treatment of how to systematically overcome judgement errors in recruiting, see the article on overcoming unconscious bias in recruiting.

For which roles are BARS suitable?

BARS can in principle be developed for any role. They are particularly valuable in areas with clearly defined behavioural requirements: sales, customer service, leadership positions and apprenticeship or trainee roles. They are less suited to highly creative activities where the quality of outcomes varies significantly and is difficult to capture in concrete behavioural anchors.

Do BARS need to be updated regularly?

Yes. Behavioural anchors reflect the state of role requirements at the time of their development. When job content changes – through new technologies, shifting customer needs or organisational restructuring – the anchors should be revised accordingly. A review every two to three years is recommended, as well as following any significant changes to a role. Regular assessor training sessions are a necessary complement to maintain the quality of application over time.

Conclusion

Behaviorally Anchored Rating Scales are a powerful instrument for more objective, fairer and legally defensible personnel appraisals. By replacing abstract rating levels with concrete behavioural descriptions, they reduce systematic appraisal errors and improve the comparability of assessments – whether in performance reviews, structured interviews or assessment centres.

The development effort is considerable, but the impact is lasting: BARS are an investment in the quality and fairness of every appraisal process in which they are used. Anyone serious about structured personnel selection should develop BARS at least for the core competencies of their most critical roles.

Want to know how potential analysis and scientific aptitude diagnostics can meaningfully complement behaviour-based appraisal methods? Learn more about what the Aivy platform makes possible: Discover Aivy

Sources

• Smith, P.C. & Kendall, L.M. (1963). Retranslation of Expectations: An Approach to the Construction of Unambiguous Anchors for Rating Scales. Journal of Applied Psychology, 47(2), 149–155. https://doi.org/10.1037/h0047060
• Deutsche Gesellschaft für Personalführung (DGFP) (2020). Leitfaden Personalbeurteilung [Guide to Personnel Appraisal]. https://www.dgfp.de
• Nerdinger, F.W., Blickle, G. & Schaper, N. (2019). Arbeits- und Organisationspsychologie [Work and Organisational Psychology] (4th ed.). Springer. https://link.springer.com/book/10.1007/978-3-662-56666-4
• Thornton, G.C. & Rupp, D.E. (2006). Assessment Centers in Human Resource Management. Lawrence Erlbaum Associates.