Most theoretical models of memory distinguish three main systems or types: sensory memory, short-term or working memory, and long-term memory. Within each of these categories are further divisions. Sensory memory refers to the initial, momentary recording of information in our sensory systems. When sensations strike our eyes, they linger briefly in the visual system. This kind of sensory memory is called iconic memory and refers to the usually brief visual persistence of information as it is being interpreted by the visual system. Echoic memory is the name applied to the same phenomenon in the auditory domain: the brief mental echo that persists after information has been heard. Similar systems are assumed to exist for other sensory systems (touch, taste, and smell), although researchers have studied these senses less thoroughly.(Encarta reference library 2003)
We can keep information circulating in working memory by rehearsing it. Several experiments can be performed to test this. The experiment can be performed on the assumption that is the person is able to recall more he/she can be said to have more observation power. It can also be assumed that the things that are recalled are ore familiar to the person. We can recall events,things and also facts that are more familiar to us quickly than those that are unfamiliar. For example in a 1966 experiment, subjects were shown a series of 15 words, then tested for their recall of the words immediately or after 30 seconds. When tested immediately, people remembered items at the beginning and end of the series better than those in the middle, a phenomenon called the serial position effect. Memory for words at the end of the list faded when the test was delayed 30 seconds.
The experiment is simple. The players are given a series of 10 words . These words would appear on the computer screen for a brief period of 30 seconds and the players would observe what they see. After 30 seconds the words would disappear and the players would write them on papers provided to them. This process would continue several times with different words each time. The words may be meaningful or meaningless.
The experiment is performed in the following phases
The following ten words are taken. Since it is the first phase the words are simple and easy to remember:
All the five members could recall successfully all the words.
The number of words are taken in the y-axis and the persons are taken in the x-axis i.e. 1 indicates person 1 and so on.
From the above observation it can be inferred that recalling words depends upon the ease of words.
In this phase the following words are taken:
Number of words
From the table it can be inferred that the first person recalled 10 words, the second person recalled 8 words, the third person recalled 5 words, the fourth person