Attitude scales and measures of emotions can be used to understand consumer evaluations and feelings toward products and advertising. Rating scales can measure overall attitude or specific attributes, and can be comparative (e.g. blind taste tests) or non-comparative. Common scaling techniques include paired comparisons, ranking, rating scales (e.g. Likert, semantic differential), and measuring response latency. Emotions are also important to measure, as feelings can impact behavior, and can be gauged using semantic differentials, pictures, or other scales. Reliability and validity are key in evaluating measurement scales.