You have two options.
Many factors affect a person's profile results and the response focus is most likely not a significant one. However, if you're administering the assessment in a work setting there's no harm in asking the respondent to answer questions with that setting in mind. Our environment (e.g., at work, at home, with friends) does play an important role in our understanding of DiSC. But how we apply insights gained from profiles is much more the issue, not in how the profiles are constructed from respondents' answers.
No, you do not have to be certified to administer DiSC profiles. However, the publisher does offer certification for those who wish to be certified.
DiSC assessments do not predict success in employment or in particular job classifications, so they are only one data point in an array of information used to select a candidate. However, the most popular test used during the hiring process is Everything DiSC Workplace. The most often used package in hiring and recruiting is the combination of Everything DiSC Workplace and Team Dimensions.
The DiSC Group Report describes all profiles in your selected group of participants. The report includes an illustration of the group's distribution of DiSC styles and detailed information on how each individual's style may affect the culture of the group or organization. You can add respondents to your Group Report up to three times.
DiSC Classic Paper is an all-in-one 20-page booklet to respond, score and interpret results. The booklet describes the person’s primary DiSC style and helps identify one of the 15 DiSC Classical Patterns. The product was formerly known as DiSC Personal Profile System® 2800 Series.
DiSC Classic 2.0 is a 23-page, on-line report. It includes all the information of the paper booklet plus it offers personalized feedback written in an informal and conversational style that helps people understand the strengths and challenges of their behavioral styles. A Group Report is available when using DiSC Classic 2.0.
In general, the average person’s profile tends to stay fairly consistent over time. While you may find small differences in your results from one time taking the assessment to the next, you’re unlikely to experience major shifts in style. However, if it has been two years or more since you last took the profile, we recommend taking it again to ensure the most accurate and up-to-date information.
EPIC is the electronic platform that allows you to send out access to profiles via the internet. It stands for Electronic Profile Information Center.
EPIC credits describe the "currency" used in the EPIC system. Credits are needed to issue access codes for individual reports and to generate group/facilitator reports.
Inscape Publishing, the publisher of all of our DiSC assessments, is committed to maintaining the highest standards of instrument development and application through a careful research and development process. They ensure all of the instruments offer valid scores and accurate feedback to the respondent. Each instrument is designed to provide reasonably accurate interpretations or feedback based on your scores.
Research, reliability and validity of DiSC®
The following research reports provide more information on the most popular DiSC assessments:

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