EDPSY 014 Lecture Notes - Lecture 36: Multimodal Distribution, Standard Deviation, Standard Error
22 Apr 2016
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Document Summary
Standard deviation- a mathematical calculation that determines the spread of scores. Scores are distributed + or 4 standard deviations. Median- middle score (50% above and 50% below: used when we have a skewed distribution. Mode- most frequent score: in a normal distribution it is the same as the mean, bimodal distribution. Tells you that they either get it or they don"t there"s no in between. Normal distributions: 68% of the population is in the plus or minus a standard deviation average, 95% of the population is within 2 standard deviations of the mean, 2. 5% are above 2 standard deviations above the mean. Gifted and talented cut off is 2 standard deviations from the mean: 99% of population at plus or minus 3 standard deviations from the mean. Reliability: test retest reliability correlation between taking the same test at a later date. Score should remain stable 0. 0-. 99: norm reference tests are designed to give high reliability.
