Ancrage (psychologie)En psychologie, l’ancrage désigne la difficulté à se départir d'une première impression. C'est un biais de jugement qui pousse à se fier à l'information reçue en premier dans une prise de décision. Dans les débats publics, « l'effet d'ancrage » donne une prime aux personnes qui ont la capacité de prise de parole publique (expert, militant, journaliste, contestataire contre les institutions...), plus encore si leur point de vue est argumenté et que ceux qui les écoutent n'ont qu'une vague opinion sur le sujet.
Information contentIn information theory, the information content, self-information, surprisal, or Shannon information is a basic quantity derived from the probability of a particular event occurring from a random variable. It can be thought of as an alternative way of expressing probability, much like odds or log-odds, but which has particular mathematical advantages in the setting of information theory. The Shannon information can be interpreted as quantifying the level of "surprise" of a particular outcome.
Hartley (unit)The hartley (symbol Hart), also called a ban, or a dit (short for decimal digit), is a logarithmic unit that measures information or entropy, based on base 10 logarithms and powers of 10. One hartley is the information content of an event if the probability of that event occurring is . It is therefore equal to the information contained in one decimal digit (or dit), assuming a priori equiprobability of each possible value. It is named after Ralph Hartley.
