INTRO+DATASETS

process of building, cleaning, structuring datasets to analyse and extract meaning

• Ask interesting qn • Get data • Explore data • model data • visualize and communicate results

• get many data sources • understand how data collected • use statistical models • understand correlations • good comm skills

-random experiments that produce a series of possible outcomes (can be infinity outcomes)

• sample space(ohm symbol)(set that contains all possible outcomes. outcomes are mutually exclusive and collective exhaustive)(an event is a collection of one or more outcomes–subset of sample space) • probability fraction p(A) assigns event A a no. between 0 and 1. Complement of event A= A^c– p(A^c)=1-p(A)

probability of outcome A given that event B (DENOMINATOR)has occurred.

A and B are independent if the occurrence of B provides no information about A. intersect of events A and B =P(A)*P(B)

variable is any characteristic observed in a study. summary of ALL outcomes in a random process

there is meaningful distance between any 2 points of data

• ordinal - nominal

• discrete (separate numbers) - continuous (possible values form an interval)

list of possible outcomes+associated probability

probability that the discrete variable is less than or equal to a particular value.

Probability density function (PDF) is the probability that the value of a continuous variable falls within an interval.

Cumulative distribution function (CDF) is the probability that the variable is less than or equal to a particular value.

category with the highest frequency

One vertical bar for each possible category that could occur, with the height proportional to the frequency of that category.

• Divide the range of data into intervals of equal width. • Count the number of observations that fall within each interval. • Label the intervals on the x-axis. • Draw a bar over each interval

sensitive to extreme observations

average squared deviations from the mean

• 68% of observations fall within +-1SD • 95% fall within +-2SD • almost all fall within +-3SD(check for outliers)

range between upper and lower quartiles (robust to outliers)

min , lower quartile, median (X0.5), upper quartile, max (min N max NOT considering outliers)

if a particular value for a certain variable(response/dependent) is more likely to occur with certain values of another variable(explanatory/independent)