Eye chart number). The denominator indicates the distance in feet at which a person with normal vision could stand to correctly identify the same symbols identified by the person tested. For example, a visual acuity of 20/20 is considered normal. Numerous types of eye charts exist and are used in various situations. For example, the Snellen chart is designed for use at 6 meters or 20 feet, and is thus appropriate for testing distance vision. There is often also a need to test a subject's vision at near or occupational tasks (such as reading or computer use). For these situations, a Rosenbaum
Name-letter effect most commonly used one is a letter rating task, which involves having participants judge all the letters of the alphabet. Even within this method there are variations in the instructions (how much you like the letters or how attractive you find them), in the rating scales (five-point, seven-point, or nine-point), in the order of the letters (random or alphabetical), and in data collection (paper-and-pencil or computer-based). There is no standard algorithm for calculating implicit self-esteem. At least six algorithms are in use. In their meta-analysis of the name-letter effect, Stieger, Voracek, and Formann recommend using the ipsatized double-correction algorithm (the