One common way of studying human emotion is to obtain self-reports from participants to quantify their current feelings or average feelings over a longer period of time. These are referred to as measures of affect or measures of emotion. Even though some affect measures contain variations that allow assessment of basic predispositions to experience a certain emotion, tests for such stable traits are usually considered to be personality tests. One common way of studying human emotion is to obtain self-reports from participants to quantify their current feelings or average feelings over a longer period of time. These are referred to as measures of affect or measures of emotion. Even though some affect measures contain variations that allow assessment of basic predispositions to experience a certain emotion, tests for such stable traits are usually considered to be personality tests. Scholarly work has noted the problematic nature of using the terms “emotion”, “affect” and “mood” interchangeably. A lack of thorough understanding of these concepts could influence the choice of measures used in assessing the emotional components of interest in a study, leading to a less optimal research result. The differentiation among these key concepts in affect research in the current era is becoming increasingly important, as consistent effort has been made to move out of the stage of using these constructs interchangeably. Affect refers to the mental feeling from inside the body that underlies all emotional experience. It varies in valence (from unpleasant to pleasant) and arousal (from deactivated to activated). While affect is a general term, core affect is one of the fundamental components that constitute a basic emotional unit, what they termed as prototypical emotional episode, as proposed by Russell and Barrett in their seminal work. They suggest that besides core affect, other ingredients such as behavior facial emotional expression are also parts of one emotional unit. Emotion is a “complex set of interrelated subevents concerned with a specific object”. In other words, emotion is a physical compound constituted by a number of more basic ingredients. This view comes from the psychological constructionist tradition, a more recent and theoretically rich approach. Earlier tradition in the study of human emotion can be broadly divided into two, namely appraisal and basic emotion approach. The appraisal tradition views emotion as a short-lived experience that involves cognitive appraisal as its defining feature, while the basic emotion approach believes that there are exclusive categories in emotional states. Mood distinguishes from emotion in duration and intensity. Generally, mood is viewed as more persistent and less intense than emotional state, and as a result more stable. It falls between the fleeting emotional states and more enduring trait. One categorization of affect measures is based on whether the measure focuses on transitory state or relatively stable trait dimension. The instructions of measures provide different timeframes to examine the continuum from state to trait. For example, the question framed as 'In your daily life, how often do you feel...?' is measuring an enduring trait, while the question 'How do you feel right now at this very moment?' is a measure for emotional states. Another way to categorize the measures is to differentiate between distinct-states approach and dimensional approach. Examples of measures using distinct-states approach include theProfile of Mood States (POMS2), and the State-Trait Anxiety Inventory. Dimensional approach adopts the psychological constructionist tradition, but has been criticized for assuming the “emotions can be reduced to pleasant and unpleasant states or that affect alone provides a sufficient explanation for emotion”. Examples of the dimensional approach measures include the Positive and Negative Affect Schedule (PANAS) and the Self-Assessment Manikin. A three-step process is proposed for choosing an affective measure. Firstly, consider what the specific construct it is that you want to measure. Secondly, choosing the theoretical framework in accordance with the construct. Lastly, evaluate the psychometric feature of the measures available (e.g. reliability, validity, etc.). The Affective Slider is an empirically-validated digital scale for the self-assessment of affect composed of two slider controls that measure basic emotions in terms of pleasure and arousal, which constitute a bidimensional emotional space called core affect, that can be used to map more complex conscious emotional states.