People hear “assessment center” and picture a building. It is a method. The hard part is never the day itself. It is the weeks before: deciding what exactly you want to see and in which exercise you will see it.
Below: what it is, when it is worth the effort, the exercises, and how to run and score one. To plan your own, jump to the competency × exercise matrix builder.
Below: what it is, when it is worth the effort, the exercises, and how to run and score one. To plan your own, jump to the competency × exercise matrix builder.
What is an assessment center?
An assessment center is a multiple evaluation process. The name comes from the place where AT&T assessed the managerial potential of its employees. It can last from a few hours to several days.
Five features make an event an assessment center:
Five features make an event an assessment center:
- A group of participants. Most often four to six people, twelve at most. A center for one person is possible as a final check before hiring.
- Varied exercises. Simulations built on real work material, usually with an interview and sometimes with tests.
- A team of trained observers. A mix of HR people and line managers, all trained for the role.
- Predefined behavior. Observers assess against a fixed list of job-related competencies, not against a general impression.
- A joint decision. Ratings are agreed when the observers sit down together and go through all the data.
Assessment center vs development center
The exercises can be identical. The purpose is different.
- Assessment center — selection. It ends with a decision: hire or not, promote or not. Participants are compared with a standard set in advance, the assessor acts as a judge, and feedback comes later.
- Development center — diagnosis. There is no pass mark. It looks for strengths and development needs, the facilitator gives feedback during or at the end of the event, and the result is an individual development plan.
When do you need an assessment center?
The four classic uses: selecting graduates, hiring outside candidates for senior roles, choosing people for promotion, and career development.
From practice I would add a fifth: when you cannot judge people by results. A new manager once took over a unit of 50 people at the TV channel where I worked. There were problems with turnover, efficiency and pay. He asked HR for a way to assess competencies, behavior and knowledge, not only results. These employees hardly worked with colleagues — their job was to find guests for the shows and people for the studio audience — so a 360 review had nobody to ask. We ran an assessment center instead: a role play where you had to persuade a person to come on a show as its hero, a list of the competencies that mattered, and a basic computer test, because they prepared reports.
When is it not worth it? When the purpose is vague. Launching a center from the first idea takes about four months, and the cost has two parts: development and running the sessions. If nobody can say what decision the results will feed, do not start.
From practice I would add a fifth: when you cannot judge people by results. A new manager once took over a unit of 50 people at the TV channel where I worked. There were problems with turnover, efficiency and pay. He asked HR for a way to assess competencies, behavior and knowledge, not only results. These employees hardly worked with colleagues — their job was to find guests for the shows and people for the studio audience — so a 360 review had nobody to ask. We ran an assessment center instead: a role play where you had to persuade a person to come on a show as its hero, a list of the competencies that mattered, and a basic computer test, because they prepared reports.
When is it not worth it? When the purpose is vague. Launching a center from the first idea takes about four months, and the cost has two parts: development and running the sessions. If nobody can say what decision the results will feed, do not start.
Assessment center exercises: the main types
The exercises are the core: they let a person show the behavior the job needs.
One rule if you want to see leadership in a group discussion: give the group several small problems and appoint a different leader for each. Otherwise one person dominates and the rest give you nothing to record.
- Cooperative group discussion. Everyone gets the same information and no roles; the group analyzes a problem and gives recommendations within a time limit.
- Competitive group discussion. Each person also holds information only they know and competes for limited resources. The task is double: win the most for yourself and help the group reach the best solution.
- Presentation. Prepare and deliver. The simplest form is a self-presentation: five minutes to prepare, five to speak.
- Role play. A one-to-one meeting with a role player: a client, a colleague, a subordinate. In my example a manager talks to a “difficult” employee with ten minutes to prepare and twenty for the conversation.
- Fact-finding. A short description of a situation and an expert who answers only specific questions. Five minutes to read, fifteen to ask, five to present the decision, ten to defend it.
- In-basket. A folder of 10 to 40 letters, reports and notes. The participant sets priorities, delegates and writes instructions for each item.
- Written analysis of information. Two or three pages of text with tables or charts and a report to write.
One rule if you want to see leadership in a group discussion: give the group several small problems and appoint a different leader for each. Otherwise one person dominates and the rest give you nothing to record.
How to match exercises to competencies
You build a table: competencies in rows, exercises in columns, a mark where the competency can really be observed.
Three rules from the course:
Three rules from the course:
- Start from the job. Job analysis shows what separates successful people in this role from less successful ones. Keep up to five competencies and describe each with positive and negative behavioral indicators.
- Every competency is measured by at least two tools. The most important ones — by three, the rest — by one or two.
- Mix the formats: at work people act in groups, one-to-one and alone.
How to run an assessment center: step by step
- Write a memorandum. A short document for the organization: the goals, who it is for and how participants are selected, who the observers are and how they are trained, how the results will be used and stored, who gives feedback and when, and whether reassessment is possible. Competencies come from job analysis.
- Build the matrix and develop the exercises. Form a team with line managers who know the job, write a first draft, run a pilot on people of the same level, refine, and write the observer guide with examples of positive and negative behavior for each criterion.
- Select and train observers. Training usually takes three to five days. Cut it short and you pay later with long arguments about what a criterion means.
- Plan the day. Six people is the best size for a group discussion. The number of observers depends on the exercises and criteria: from 0.5 to 2 per participant, and for a selection center one assessor for every three to five participants. Rotate observers between participants.
- Brief the participants. Observers will record behavior, nobody needs to play a role, most tasks are timed.
- Run the exercises. Observers stay neutral: no nods, no smiles, no comments on results, no discussion with each other until the end.
Should you bring in consultants? You can at any stage. At Wargaming the company was growing fast and managers were appointed quickly and without common criteria; many great specialists turned out to be poor managers. A project team of about ten HR people, me included, chose DDI as the provider, defined an assessor profile, selected assessors from our own employees and trained them. They were certified and could then run the assessment themselves.
How to score an assessment center
Observers work in four steps:
- Observe. Watch and listen. Facts, not interpretations.
- Record. Write down what is said, verbatim where possible. “He was not interested” is a guess. “He did not speak for ten minutes” is a record.
- Classify. Right after the exercise, sort each piece of behavior by competency and mark it as a positive or negative example. Silence after a direct question is also data.
- Evaluate. Only now give a rating for each competency in this exercise, on a scale all observers read the same way.
Rating scale
5 — very high level of ability
4 — more than acceptable
3 — acceptable
2 — less than acceptable
1 — unacceptable
At the start of training the same behavior often gets a 2 from one observer and a 4 from another — the reason to practice before the real day.
After the last exercise the ratings go into a results matrix for each participant: competencies in rows, exercises in columns. Then comes the observers’ discussion. Participants are taken one by one, and for each competency the group looks at the evidence from all exercises and agrees on a final rating.
The chair has three jobs:
After the last exercise the ratings go into a results matrix for each participant: competencies in rows, exercises in columns. Then comes the observers’ discussion. Participants are taken one by one, and for each competency the group looks at the evidence from all exercises and agrees on a final rating.
The chair has three jobs:
- ask for the behavior behind every rating;
- let senior observers speak last, so their status does not set the score;
- keep out anything learned outside the center. The rating rests only on what was seen that day.
What to do after the assessment center
The report. For a hiring decision it is short; for a development center it is detailed — from 1 to 15 pages. It gives the final rating for each competency with the behavior that supports it, two or three main strengths and weaknesses, and development recommendations.
Feedback. Give it to everyone, including candidates who did not get the job, and as soon as possible. A personal meeting of one to two hours works best. The direct manager should not be the one who delivers it.
The check. Later, compare the ratings with how people actually perform, for example with their 360 feedback. If the results go into a talent review, see also the guide to the 9-box grid.
Feedback. Give it to everyone, including candidates who did not get the job, and as soon as possible. A personal meeting of one to two hours works best. The direct manager should not be the one who delivers it.
The check. Later, compare the ratings with how people actually perform, for example with their 360 feedback. If the results go into a talent review, see also the guide to the 9-box grid.
Common assessment center mistakes
- No clear purpose. Selection and development need different designs.
- One exercise per competency. A single observation is an episode, not evidence.
- Untrained observers. They write impressions instead of behavior, and the final discussion turns into a contest of opinions.
- Outside knowledge in the room. A favorite who performed poorly gets rescued by reputation.
- No feedback. People gave you a day of hard work and heard nothing back.
The full path — job analysis, ready exercises, observer training, the forms for the day and the report template — is in my Assessment Center Course: Employee Evaluation Training.
