Assessment tools do not always give you accurate information about your client. Employees of a client can give false or "politically correct" information that may not reflect their true needs. For example, when using tools such as surveys or questionnaires to assess the management practices in an organization, you may find that employees may falsify information for fear of punishment. Psychometric tests are also not accurate tools as they assess people based on personality, which can be very unstable. This instability may not provide a true picture of the employees' needs.
Assessment tools and techniques can be very costly. High costs may prevent you from extensively evaluating the needs of a client such as a business company so as to gather adequate information. For example, focus groups, which can take a couple of weeks to conduct, can cost as much as $2,000 to $3,000. Personal interviews can cost $50 and up per interview, while telephone assessment costs may range between $4,000 and $6,000.
Various assessment tools such as interviews with employees about other employees, performance reviews and observation can be biased. As you assess employees through observation, you will gain first-hand information. But your assessment can also be blurred by your background prejudices and lack of information. Also, a client such as a business owner may not always give unbiased information about his employees (such as in performance reviews), about his business practices or about other issues going on in the company.
Assessment tools usually gather overall and generalized information about a client, who can be a business owner or an organization. For example, in an organization, different employees have different training or professional development needs. Developing an individual assessment for every employee is not always feasible, and so assessment tools use general samples to reach a conclusion about employee needs. But generalized information may not be adequate enough to meet the needs of these employees.