Knockout questions determine if a candidate is suitable for a position based on the answer given to the question. Depending on the answer given to a knockout question, the candidate may be classed as a preferred candidate and therefore, the candidate's details will be imported into the system and the candidate will enter a referral workflow. Alternatively, the candidate may be subject to one of the following knockout actions:
discard
move to knockout stage.
The discard action rejects the candidate altogether. This means that the candidate's details are not imported into the system and the candidate will not be considered for the job.
The move to knockout stage action causes the candidate's details to be imported into the system and the candidate is moved into a knockout stage within the referral workflow. A knockout stage is a stage within the referral workflow process that is mapped to the Knockout channel. The knockout stage is used to group those candidates who are not the preferred candidates for a job but who may be referred if a more suitable candidate cannot be found or who may be suitable for similar positions that need to be filled.
To understand how knockout questions can be used, consider the following scenario.
A client is seeking candidates who preferably have more than five years work experience in a specific job role. However, if a suitable candidate cannot be found, the client will consider candidates who have a minimum of three years experience. Therefore, the questionnaire for the job role could include a question such as the following: 
...
The sample question shown above could be configured as a knockout question, whereby the discard action could apply to answer C the ‘0 - 1 year' answer, and the move to knockout stage action could apply to the '1 - 2 years’ answerB.
A candidate who selects answer A ‘2 - 4 years' or ‘Over 5 years’ is considered to have the preferred level of experience and therefore is not rejected or moved into the knockout stage. Instead, the candidate is moved into a specific referral workflow stage depending on the score the candidate achieves on the questionnaire.
There can be multiple knockout questions on a single questionnaire and therefore a candidate who is not rejected or placed into the knockout stage based on the answer for one knockout question may still be discarded or placed into the knockout stage based on an answer to another question on the same questionnaire. A candidate is not discarded or moved to the knockout stage until the entire questionnaire is completed.
Some question types can be configured to allow selection of multiple answers. It is possible to apply knockout actions to one or more answers within such questions. If a candidate selects multiple answers and a knockout action applies to one or more of the answers selected, the candidate will be discarded or moved to the knockout stage accordingly. The discard action takes precedence over the move to knockout stage action. Therefore, if a discard action applies to one of the selected answers and the move to knockout stage action applies to another of the selected answers, the candidate will be discarded.
Knockout actions can be applied to questions with the following answer types:
numeric
yes/no
value list
date.