PSYC 111 Lecture Notes - Lecture 3: Myelin, Statistical Significance, Descriptive Statistics
Document Summary
Statistical reasoning in everyday life: researchers use descriptive statistics to organize their data meaningfully. Researchers want to find out income levels of ages 20-30. End up seeing a data set: measures of central tendency. Include a single score that represents a set of scores. Mean: average of a distribution, obtained by adding the score and then dividing by the number of scores. Can be distorted by a few atypical scores. Median: middle score, half the scores above and half the scores below. Mode: most frequently occurring scores in a distribution: describing data. Measures of variation reveal similarity or diversity in scores. Range: difference between highest and lowest scores. Standard deviation: computed measure of how much scores vary around the mean score. Normal curve (normal distribution): symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean and fewer and fewer near the extremes.