What is a Problem Solving Test (PST) and why is it used?
A growing number of top tier firms have started using written problem solving tests (PSTs) as a part of their recruiting process
Although the most feared part of the consulting interview process is the classical case interview, the PST is also considered extremely challenging!
Problem Solving Tests are generally employed for two main reasons:
- To test additional skills for succeeding in consulting that are challenging to test in a case interview
- To allow screening of a larger pool of applicants because online tests have negligible costs for each incremental candidate compared to conducting case interviews
The following are certain attributes consulting firms are testing in the PSTs:
- Ability to cope with ‘information overload’ consisting of data that may/may not help in answering the question
- Ability to quickly read charts and grasp the key message
- Ability to NOT easily get swayed by data that implies some information but cannot be inferred without making assumptions
Moreover, this test provides an objective data point for the interview process. In fact, these data points are especially important for borderline candidates.
Depending on firm and office, Problem Solving Tests are conducted at different stages of the interview process
Depending on company and location, the written tests are conducted at different stages of the interview process and for slightly different purposes. Tests can be used to screen candidates prior to the actual interview process, as a route to pass from one stage to another or as a substitute for another case interview. In all cases, you do need to pass these tests to reach the next stage.
As a screening tool prior to case interviews
For example, McKinsey and Oliver Wyman use PST as a screening tool prior to case interviews. This technique allows companies to test candidates by giving an online version to be taken remotely (e.g., Oliver Wyman) or on-site at the firm's office (e.g., many McKinsey offices).
Typically, only candidates whose accomplishments have persuaded the recruiters that the candidates might be a good fit are invited to take the test. This test is the only obstacle between the candidate and the invitation to an actual case interview. Since there is no case interview to calibrate the candidates’ performance, there is usually a cut-off score for the test. Though there is anecdotal evidence for candidates that have been invited to interviews even after failing these tests, this is very infrequent.
As a route to the next stage
Some boutique firms use this technique to determine whether the candidate can be moved on to the next stage. Candidates who have successfully completed the first round of interviews can be requested to complete a written test (e.g., PST) to determine if they should be invited to a second round of interviews. If the firm is doing the selection process in a single day, candidates could be asked to take a test on site followed by case interviews to assess the candidates' overall performance.
In general, it is challenging for candidates to compensate poor test performance by a superior case interview performance by itself.
Problem Solving Tests as a substitute for another case interview
For example, German McKinsey offices use a PST variant as part of the first round interview process. At the beginning of the interview day, candidates receive a schedule that provides specific information about their interviews. One of the slots in their schedule could be for the PST and only 1 or 2 candidates take the PST at the same time.
Candidate evaluation takes place once a set of interviews and the PST are completed. That means that the test is evaluated together with the other interviews to form a comprehensive picture. This set up actually gives slightly lower importance to the PST: here, it can be assumed that, although a good test result cannot substitute a poor interview performance, a borderline PST candidate that delivers a series of stellar interviews still might get an overall pass.
Problem Solving Tests can be more or less similar to consulting cases
So, what are the companies looking for specifically in these tests? Well, admittedly a little bit dissatisfying, we found the most common answer to be "it depends". On one hand those tests are designed to cover one or more personality characteristics (performance under pressure, time management etc.) and on the other hand the tests cover specific skills pertinent to consulting (business cases).
Highly consulting-specific tests:
Tests that are highly specific to consulting typically design their questions to be similar to problems that you might encounter in face to face case interviews or can even be derived from real life projects as a consultant. Their questions are typically designed to mirror a case study with a hypothetical client (e.g., ‘BurritoCo’).
McKinsey’s PST is an example of a test that covers multiple dimensions. Other companies, such as Oliver Wyman, cover only one or a few dimensions, such as chart reading and numerical reasoning with numbers.
Not consulting-specific tests:
Tests that are not consulting-specific typically use questions that are not designed to mirror interview cases or even business problems. Examples include GMAT-style math problems and/or brain teaser style questions (see our article about typical questions in written consulting tests).
- Written tests such as the PSTs are being increasingly utilized by a range of consulting firms
- Their importance for the overall interview process varies across firms, offices, and from candidate to candidate
- Tests are designed to evaluate multiple skills and can be based on business studies similar to case interviews