Memory, broadly speaking, refers to our ability to retain information. There are various types of memories that a person uses to retain information of his/her interest. Some on permanent basis and rest is on temporary basis. Long term memory which is also a knowledge base of the user stores the information on permanent basis whereas short term memory (STM) allows the person to retain items for a short period of time. As per the research, a typical adult’s memory span is approximately 7 (between 5 and 9) unrelated items, called chunks (Miller, 1956). A person can retain this information in the short term memory for about 18 seconds without paying attention to it. After this period, information can be lost or replaced with new incoming information in the short term memory. Whenever user want to interact with the world using the information from the short term and long term memory, a third type of memory i.e. working memory (WM) comes into picture which helps us make decisions, and remember and retrieve facts. Since user actively use these memories while interacting with the computer systems, a designer have to carefully consider their respective limitations while developing the interface for optimal performance.

User satisfaction is one of the key aspects that measures the success and popularity of a computer system or website. One important factor that contributes to user satisfaction is the response time of the system. Response time is generally measured as the number of seconds it takes from the moment a user initiates an action, usually by pressing the Enter Key or a mouse button, until the computer begins to present the results (Shneiderman B and Plaisant C., 2009). Once the system response is completed and observed by the user, he/she will start thinking on the next action in the process. Time taken between the computer’s response and the user’s initiation of next item is commonly referred as user think time. User’s short term memory along with the working memory plays an important role in this human computer interaction. User uses the short term memory in conjunction with working memory for processing the specific information to produce desired output. Short term memory possesses all the necessary inputs whereas working memory is used to generate and implement solution.

As explained earlier short term and working memory are highly volatile and any disruption or significant delay can cause loss of information or it requires memory to be refreshed. When the user is waiting for the response and if the