Assessment in counseling and guidance is a systematic process used to collect information about an individual’s abilities, interests, personality, behaviour, and problems for effective decision-making. However, the accuracy and usefulness of assessment can be affected by various errors. These errors may arise from the counselor, the assessment tools, the individual being assessed, or the conditions under which the assessment is conducted. One major source of error is the improper selection of assessment tools. A counselor may choose a test that does not match the purpose of assessment, age, cultural background, or educational level of the client. Using an inappropriate instrument can lead to inaccurate conclusions about the individual’s abilities, personality, or needs. Therefore, counselors must select standardized and reliable tools suitable for the specific assessment purpose. Errors can also occur due to lack of reliability and validity of assessment instruments. Reliability refers