Another issue could be seen as the historical constraints. Originally developed as a measure for moods, the items in PANAS represent a mixture of different constructs like affect, emotion and mood. Some items do not fall into any of the categories, for example, distressed and nervous. The expanded version of PANAS is called PANAS-X and includes 60 instead of 20 emotion words (items). The instructions and the answer format are identical to the short PANAS. However, PANAS-X not only measures general positive and negative affect, but also four basic negative emotions (fear, hostility, guilt, and sadness), three basic positive emotions (joviality, self-assurance, and attentiveness), and four more complex affective states (shyness, fatigue, serenity, and surprise). The internal consistency (Cronbach's coefficient alpha) for all of these scales can be regarded sufficient (with all α≥.74), that is people report that they experience all emotions that make up one of the scales with similar strength. The manual of the PANAS-X offers further extensive psychometric information. The International Positive and Negative Affect Schedule Short Form (I-PANAS-SF) is a shortened version of the PANAS, intended to only contain cross-culturally well understandable emotion words. In contrast to an earlier ad-hoc created short forms of the PANAS, the I-PANAS-FX has been developed in a multi-study procedure including studies with participants from 16 countries. In the I-PANAS-SF, positive affect is measured using the words: active, alert, attentive, determined and inspired; negative affect is measured with the words: afraid, ashamed, hostile, nervous and upset. The I-PANAS-SF is intended for general use in research situations where either time or space is limited, and for international use with participants whose native language is not English. The State-Trait Emotion Measure (STEM) is a more recently constructed measure that is explicitly framed to assess emotions at the workplace. The STEM assesses stable (trait) and current emotions (state) for five positive and five negative emotions: affection, anger, anxiety, attentiveness/energy, contentment, envy, guilt/shame, joy, pride, and sadness. As opposed to the PANAS, people filling out the STEM are not only provided the emotion word, but also (1) a definition of that emotion, and (2) several example situation in which that emotion is usually felt from the work setting.