Moral of the story, hire someone to help with this. # Descriptive Statistics - - Almost all studies need descriptive statistics - Parameters - Demographics, salary schedules, etc. can all be statistics - Descriptive research is a type of descriptive statistics - Numerical Data - Numbers - SAT, ACT scores, temperatures, Money spent on sports equipment - Categorical Data - Percent minority, percent male, etc ## Summarizing Data - Distribution - how data are distributed. Visual representation of the data - Frequency Polygons - looks like a line graph - Positively skewed polygon - trails off in a positive direction - Negatively Skewed polygon - trails off in a negative direction - Histogram - Bar graph - Normal distribution - symmetrical - Averages - all the same on a normal curve - Mode - most frequent number - Median - middle one - Mean - average - ![[CleanShot 2024-02-27 at [email protected]]] - Measures of central tendency - Mean can be the same, but different spread or different mean. - Range - high and low - 5 number summaries - box plot - Standard Deviation - 1 sd is ameasure of how spread out the thing is. - 3 standard deviations is 99% - 68% fall within the 1 standard deviation ## Stem-Leaf Plots display that organizes a set of data to show both its shape and its distribution Take the results, put the tens in one column and the ones in the other column. ## Correlation Does Not Equal Causation - Scatterplot - relationship between two quantitative variable - Outliers - unusual exception - Pearson's R R=1 is perfect correlation, 0 is no correlation -1 is perfect negative correlation [[EDUC 7710 Research methods]]