THE CUE SUMMATION PRINCIPLE OF LEARNING (realism theory) has to do with the deployment of realistic features of a given reality in order to enhance its comprehension or meaning. This principle predicts that learning increases as the number and types of cues increase (Moore, Burton, and Myer, 1996.pp. 851-875). For example, consider a scenario on the perception of time and time-clock among the Hmong people:
though clocks are a common device for telling time and they govern the behaviors of most U.S. Americans, many people live in cultures in which there are no clocks and no words for this concept. Some Hmong people, upon moving to the United States, initially had difficulty in the PRINCIPLE OF LEARNINg (realism theory) has to do with the everyday experience of telling time with a clock (Lustig and Koester, 1996, p. 166).
What follow are examples of cue summation at three different levels of instructional units designed to teach learners such as the would-be immigrant Hmongs the basic features and function of the time-clock.

Imagine you have never seen a clock before. You are reading about the time-clock for the first time without any illustration or demonstration of this abstract concept. Read on and note how it feels:
1. A clock is a time-measuring device, usually circular in shape, with markings representing different units of time: seconds, minutes, and hours.
2. Pivoted together at the center are three mobile hands, or pointers, for the second, minute, and hour. These hands stretch out, pointing towards the time unit markings as they rotate at varying speeds, in one direction.
3. The pointer for the second, usually brightest, is the thinnest, longest, and fastest. It takes this pointer 60 successive short movements, or ticks, each representing one second, to complete a full rotation of 360°, or one minute. As it completes a full rotation and comes to the top-most number, 12, the minute hand moves one point, or one minute. 
4. The minute pointer is shorter, wider, but slower than the second's. Like seconds, minutes are read on a 60-point scale in relation to the pointer. The minute hand makes 60 barely noticeable movements of one minute each, in one full rotation of 360°, or one hour. As it completes a full rotation and comes to the twelfth number, the hour hand moves one-twelfth point to align with a number, suggesting the time of the day.
5. The shortest and widest pointer is the hour's. Unlike the second and the minute, the hour hand is read against a 12-point scale, each point representing one hour. The hour pointer moves so slow you can hardly perceive. As it aligns with a number on the 12-point scale, both the second and the minute hands point at the top-most number, the twelfth point. At this point, the number at which the hour hand points, signifies the hour of the day.

Learn about the time-clock and its function using a quick time animation. Compare the effects of the cues summated here (text, visuals, color, motion, speed, and the direction of rotation; the naration, sound of ticks, and the number of sound beeps for telling time) on your comprehension of the time-clock and its function. Simply click on the Multimedia (Verbal, Aural, & Dynamic) button (below) to start the animation movie:

Derry-Joe Yakubu, Ph.D, Visiting Adjunct Professor, Educational Tech., SDSU