Hick's Law

Hick’s law was initially proposed in 1952 and states that the reaction time is increasing in the number of alternative reactions-stimuli.   In other words when somebody is faced with making a decision, the greater the number of potential choices-decisions the longer it will take for him to make a choice.
According to Hick’s law the reaction time is the time interval between the presentation of the stimulus and the beginning of the response to it. The main factor that affects the response time is the number of possible stimuli that are presented (each one has its own response).
The actual formula he came up with is:
Reaction Time= Movement Time + Processing Speed · log2 (n),
(where Processing Speed · log2   is the time taken to come to a decision, n is the number of choices and movement time is the total time that is not involved with decision making).
We can see that the relationship between reaction time and number of options is logarithmic.
Hick revealed that the reaction time increases by the number of possible responses until it gets to a point where the response time remains constant despite the increasing number of possible responses.
The time it takes to process a certain amount of information is known as the growth rate of information in Hick’s law. The needed time grows exponentially when a person has to choose from several options. For ever two options the time it takes to make a decision doubles if you add a third.
Hick’s law can be used to obtain an estimate of the time one needs to take a decision in an interface user’s menu. It constitutes a justification for decisions in designing menus. In digital media it is relevant to the interaction between speed and accuracy. If the users are requested to move as quickly as possible they are going to make more mistakes. If they are asked to be accurate they will need more time.
 Hick’s law can be used to obtain an estimate of the time one needs to take a decision in an interface user’s menu.
An important point to make is that Hick’s law is relevant for simple applications where the decision-making or the response-reaction does not require a lot of thought, study or research in depth. In such cases it is required for the decision maker to invest more time to study the available alternatives and make a choice.


There are many examples of Hick’s law application in our lives, such as in restaurants, which have a set number of food choices in their menu. They change their menu often since they want to offer more recipes, but they don’t put them altogether in a menu because they do not want their clients  to spend too much time in choosing food.  On the other hand Hick’s law does not apply in multiple choice based tests where the students have to read and think of the questions and alternative answers.  In digital media we come across many cases where Hick’s law is applicable. Most simple menus of video games, TV, websites etc are designed taking into account Hick’s law. A characteristic example is the design of a trade ticker in the webpage of an on line broker. Hick’s law is applies in that because timing is of great importance when you trade stocks. The menu is designed to give the user a very limited set of options instead of a more complicated menu with all the orders available to the trader.






Hick’s law applies in many aspects of my job as an educator. Considering that I have worked as a kindergarten teacher in a classroom with 29 children, time was very valuable. I have always tried to give my students as fewer alternate choices as possible so they wouldn’t have to spend much time to decide.  Usually this happened in games and in many activities that could take place through simple reactions-responses such as “yes” and “no”. I would not use Hick’s law in designing activities that aim to learning numbers or letters because there isn’t an option to limit the choices. All numbers and all letters have to be taught in the right order.  The majority of activities that take place in kindergarten can be designed considering Hick’s law not only to save time, but also because it is easier for young children to make decisions when they have a few alternate options.




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