C207 WGU Data Driven Decision Making

Descriptive - answer-Past data only; Not predicting or optimizing Predictive - answer-Past to predict the future; Predicting, no optimizing Prescriptive - answer-Past to predict the future and optimizing Omission - answer-Missing information Out of Range - answer-Doesn't match the data or not true Reliable - answer-Constant and repeatable. A measure of the instrument Valid - answer-Measures what is intended to be measured Measurement bias - answer-Includes representative sample, random, large enough sample Information bias - answer-Ignore the purpose of the information collection; not truthful answers Big Data - answer-Both structure and unstructured; to large to process using traditional database and software techniques Data mining - answer-Process of discovering pattern in large data sets Why collect big data? - answer-Used to encourage buying behavior Analytics - answer-the extensive use of data, statistical and quantitative analysis, explanatory and predictive models, and fact-based management to drive decisions and and add value Variable - answer-An expression that can be assigned to data Continuous data - answer-Data that can lay along any point in a range of data (age 22.6 old) Discrete data - answer-Whole values only and clear boundaries Nominal data - answer-Categorical data used to label subjects in a study; discrete (male female) Ordinal data - answer-Allows you to place objects on some in some kind of order according to some quality; discrete (black belts 3rd degree higher than 1st degree) Interval data - answer-has order; all objects are equal interval apart; no natural zero point and zero does not represent the absence of the property measured; Continuous (time, date, temperature) Ratio data - answer-Has a unique zero point - numbers can be compared as multiples of one another, continuous (income, stock, repeat customers) Observational studies - answer-used when impractical and impossible to control the conditions of the study Prospective cohort study - answer-Observe people going forward in time from the time of their entry into the study Experimental studies - answer-All variable measurements and manipulations are under researcher's control. Experimental studies: Experimental units - answer-Subjects or objects under observations Experimental studies: Experimental treatments - answer-Procedure applied to each subject Experimental studies: Responses - answer-Effects of the experimental treatments 1st step of statistical experiment - answer-Identify the experimental units from which you want to measure something 2nd step of statistical experiment - answer-Id the treatments and controls that you will use on control group 3rd step of statistical experiment - answer-Generate a testable hypothesis construct validity - answer-study actual measure what is being investigated content validity - answer-Construct measures what it claims to measure Internal validity - answer-Biases may have entered the study Blind study - answer-participants are not told if they are in treatment group or control group Double blind - answer-neither treatment allocator nor participant know which group participant is in Triple blind - answer-participant, allocator and response gather do not know which group the participant is in Random errors - answer-occur because of random and inherently unpredictable events in the measurement process Correlation - answer-extent or degree of statistical associations among two or more variables systematic errors - answer-errors in measurement at are constant within a data set, sometimes caused by faulty equipment or bias Skewness - answer-a measure of the degree to which data "leans" toward one side Not a truly representative sample - answer-sample not representative of entire population Response bias - answer-respondents say what they believe the questioner wants to hear Conscious Bias - answer-When surveyor actively seeks a response; Researcher manipulates phrasing of question Missing data and refusals - answer-Sample gets lost or subjects refuses to contribute; distorts survey data when demographic is missing, leads to false conclusion Association and Causation - answer-the mistaken assumption that because two events seem to occur together, one causes the other Training and test data - answer-Data used to form hypothesis is used again to test hypothsis Unfounded assumptions - answer-Assumption is made that has not been proven Faulty operationalization - answer-Occurs when the development of specific research procedures that allow for observation and measurement of abstract concepts is flawed. Lack of binding - answer-when users fail to place barriers between themselves and subjects and influence behavior Confidence interval - answer-Range around a sample that has a specific probability of containing the true population mean Probibility - answer-The chance of event occurring Vehn diagram - answer-Mathematical sets or events visually inferential statistics - answer-making predictions and testing theories about a population from a population Descriptive statistics - answer-Statistics that are used to describe a population from the whole population Mean - answer-sum of all numbers divided by how many numbers Median - answer-middle number Mode - answer-most common number Deviation score - answer-score minus the mean Variance - answer-statistical measure of the spread of a set of data. Find difference in data point, plus mean; square them Range - answer-Take largest number from sample and subtract smallest Emperical Rule - answer-68.3% of data points will be w/i 1 standard deviation of the mean; 95.4 w/i 2 standard deviations and 95.7 will be w/i 3 standard deviation z-score - answer-a measure of how many standard deviations you are away from the norm (average or mean) z-score formula - answer-relay from memory (z-score) Quartile - answer-each of four equal groups into which a population can be divided inter-quartile range - answer-measures difference between the third and the first quartile Outlier - answer-an observation point that is significantly distant from the other data set Histogram - answer-A graph of vertical bars shows counts or numbers in each range, continuous data. Bar chart - answer-Measures distribution of discrete data bivariate charts - answer-have vertical y axis and horizontal x axis that measures 2 variables; independent variable is on the x-axis hypothesis - answer-Statement or claim about a given population Null hypothesis - answer-Argument there is no difference between two samples or that a sample has not changed over time Alternative hypothesis - answer-argument that states that a sample is not equal to the hypothesized null sample Statistically significant - answer-A result is unlikely to be caused by random variation or error T-test - answer-a statistical test used to evaluate the size and significance of the difference between two means one sample t test - answer-Used to determine if a single sample mean is different from a known population mean