Recruitment teams often compare screening tools by looking at what each format can collect. A tool may confirm availability, ask about experience, assess communication skills, create a candidate summary or help recruiters prepare a shortlist.
Those questions matter, but they should not be the only ones considered. Before evaluating how much information a screening method can provide, hiring teams should also ask how many candidates are likely to complete it.
A format may produce detailed responses from the people who reach the end, but it creates limited value when a large part of the applicant pool leaves before completing the process. Completion rate is therefore not simply a measure of convenience. It shows how much of the available candidate pipeline makes it through the first screening stage.
Zeenna’s internal candidate data shows a considerable difference between three common formats. Chat pre-screening achieves a completion rate of more than 91%, compared with approximately 45% for an AI voice assistant and approximately 40% for video assessment. These figures do not mean that one method is suitable for every role or every stage, but they do show why screening format should not be treated as a minor technical choice.
Screening formats ask different things of candidates
Chat, voice and video can all be used before a recruiter speaks with a candidate, but they do not create equivalent experiences.
Chat-based screening asks candidates to read and type. They can usually pause before answering, choose their words and complete the conversation without preparing their surroundings. Voice screening requires them to speak aloud, which may mean finding a quiet space, enough privacy and a suitable moment to discuss a job application.
Video adds further requirements. Candidates usually need a working camera and microphone, an appropriate setting and enough time to prepare how they will present themselves. They are not only answering questions but also managing how they appear and sound on screen.
The difference between these formats is therefore not limited to the information they collect. It also lies in the conditions candidates need before they can participate.
This distinction can be easy to miss when a screening process is designed from the employer’s side. All three methods may appear equally accessible because they can be opened through a phone or computer, but having access to a link is not the same as being in a suitable situation to complete the task.
Why completion rate belongs in the hiring conversation
Completion rate is sometimes treated as a product or engagement metric. In recruitment, it has a more direct operational meaning because it affects the number of candidates available for the next decision.
Consider a process in which 1,000 applicants are invited to complete an initial screening. At a completion rate of 91%, approximately 910 candidates would finish. At 45%, that number would fall to around 450, while a rate of 40% would result in roughly 400 completed screenings.
The difference is not only visible in a report. It changes the size of the pool from which recruiters can prepare a shortlist.
A low completion rate does not automatically prove that an assessment is poor, and the figure alone cannot explain why candidates leave. It should, however, encourage the hiring team to examine where candidates stop, whether the format is appropriate for that stage and whether the amount of effort matches the purpose of the screening.
Teams should also consider whether candidates are being asked to speak or appear on camera before that is necessary, and whether the same essential information could be collected through a simpler method.
The objective is not to achieve the highest possible completion rate regardless of screening quality. The process still needs to collect useful and job-relevant information. The goal is to avoid losing candidates because the format asks for more than the current hiring decision requires.
Chat works well when the first stage is mainly informational
Early screening often focuses on practical questions. A recruiter may need to know when a candidate can start, which location they prefer, whether they have the required work authorisation and whether their availability matches the role.
The process may also ask about relevant experience, motivation or language requirements. None of these areas necessarily requires a live conversation, a recording or a camera.
Chat allows hiring teams to collect this information in a structured format while giving candidates greater control over when and where they respond. In Zeenna’s internal data, chat has the highest completion rate of the three formats, reaching more than 91%.
This makes it particularly relevant when the purpose of the first stage is to confirm essential requirements and gather enough context for recruiter review. Chat can also support follow-up questions without turning the experience into another long application form. Candidates can explain their answers in their own words, while recruiters receive the information in a consistent structure.
The format still has limitations. Written responses do not reveal everything, and another method may be more useful when spoken communication is genuinely central to the role. The decision should therefore be based on what the hiring team needs to learn, rather than only on which format produces the highest completion rate.
Voice can add useful information at the right stage
Voice screening may be relevant for roles in which spoken communication forms an important part of the work. A company may need to understand whether a candidate can communicate clearly in a particular language or respond effectively to a typical customer-facing situation.
In those cases, hearing a spoken answer may provide information that a written response cannot. However, voice also changes the conditions under which candidates can participate.
Candidates need to be somewhere they can speak comfortably and without being overheard. They may postpone the screening if they receive the invitation while commuting, during working hours or in a shared environment. Unlike chat, voice is more difficult to complete discreetly between other activities.
Zeenna’s material reports an approximate completion rate of 45% for AI voice screening and describes it as a format that may work better as a complement than as the first stage. This does not mean that voice lacks value. It suggests that the method may be more effective when it is introduced only after the hiring team has established that spoken communication is relevant to the next decision.
A process could begin with a short chat-based screening and use voice later for candidates applying to roles where a spoken component genuinely matters. This allows employers to reserve the more demanding format for situations in which it adds useful information.
Video requires the greatest level of preparation
Recorded video assessments can provide recruiters with both spoken and visual information. They may be useful for roles where presentation is closely connected to the work or when the hiring team needs a structured alternative to an early interview.
At the same time, video asks candidates to manage several practical and presentational demands. They need a working camera and microphone, an appropriate environment, enough privacy and time to prepare and record their responses.
Candidates are not simply answering questions. They are also considering how they look, how they sound and what is visible behind them.
Zeenna’s internal data places video assessment at approximately 40% completion, which is the lowest result among the three formats in the comparison. Academic research does not provide one universal completion benchmark for recorded video interviews, but it does show that their design can affect applicant behaviour, anxiety, reactions and outcomes.
This does not mean that employers should never use video. It means the format should have a clear purpose. Before introducing it, the hiring team should be able to explain what useful information the recording will provide that could not be collected through a less demanding method.
More information is not always more useful information
Video may appear richer because it captures more. Recruiters can see the candidate, hear their voice and observe how they present an answer, which can make the method seem more informative than chat or audio alone.
Collecting additional information does not automatically improve the screening decision, however. Some details visible on video may have little connection to performance in the role.
The candidate’s room, camera quality, lighting or comfort in front of a lens can influence the overall impression without providing relevant evidence about their ability to do the job. Research involving hiring managers has found that candidate appearance played a role in asynchronous video interview evaluations, although communication and problem-solving skills were stronger predictors of whether candidates progressed.
This creates an important question for employers: does the additional information genuinely support assessment of the role, or does it simply give reviewers more information to react to?
When the job does not involve on-camera presentation, video may introduce additional complexity without providing an equally valuable hiring signal.
Match the format to the question being answered
Hiring teams do not need to select one screening format for the entire recruitment process. Different methods can serve different purposes, and the most suitable choice depends on what the employer needs to learn at each stage.
Chat is well suited to gathering practical information, relevant experience, motivation and answers to short situational questions. It can provide a useful starting point when the aim is to reach a large proportion of applicants without requiring them to arrange a private call or recording environment.
Voice can be introduced when spoken communication, pronunciation or verbal reasoning is directly relevant to the position. It may be more appropriate after an initial screening, once the candidate understands the opportunity and the employer has established that a spoken task is worth assessing.
Video may be justified for presentation-led or on-camera roles, or as a structured interview stage supported by clear evaluation criteria. It should not become the default simply because the technology is available.
The most appropriate format is usually the least demanding method that still provides the information needed for the decision.
A blended process can be stronger than a single-format approach
The difference in completion rates does not require hiring teams to choose one format and reject the others entirely. A blended process can use each method where it adds the most value.
For example, a short chat screening could confirm essential requirements and collect relevant context. A recruiter could then review the responses and identify which candidates should progress.
A voice task could be introduced only for roles where spoken communication needs to be assessed, while a live interview could give both sides the opportunity to ask questions and explore the role in more detail.
This approach keeps the earliest stage accessible while reserving higher-effort activities for a smaller and more relevant group. It also avoids asking candidates to complete demanding assessments before the employer has established whether they meet the essential requirements of the position.
Compare results rather than relying on assumptions
The best screening format should not be selected only because it is familiar, new or technically impressive. Hiring teams should examine how each method performs within their own recruitment process.
Useful measures may include the invitation-to-start rate, start-to-completion rate, average completion time and the stage or question where candidates leave. Teams can also review completion by device, progression to the next stage, recruiter review time and the quality of the information collected.
Completion rate should always be considered alongside the requirements of the role. A method with a lower completion rate may still be justified if it measures something essential and is introduced at the right stage. The trade-off should simply be visible and intentional.
It is also important to separate completion rate from quality of hire. Completion shows how many invited candidates finished the screening. It does not, by itself, show whether the eventual hiring decisions were successful.
Both measures are valuable, but they answer different questions.
A useful screening process must reach enough candidates
The most advanced assessment is not necessarily the most effective first step. When a format creates unnecessary practical demands, the hiring team may receive richer information from a much smaller part of the applicant pool.
Zeenna’s comparison shows the size of this difference: more than 91% completion for chat, approximately 45% for voice and approximately 40% for video. These figures should not be treated as a universal verdict on every screening tool, because results may vary according to the role, audience, invitation, question design and stage of recruitment.
The broader lesson is that format forms part of the assessment experience. It determines not only what candidates can tell the employer, but also what they must do before they can provide any information at all.
Completion rate is therefore not a vanity metric. It shows how much of the candidate pipeline the screening process actually reaches.
Before selecting chat, voice or video, hiring teams should consider what they genuinely need to learn at that stage and which format can collect that information with the least unnecessary effort. The answer may determine how many candidates remain in the process long enough to be considered.