[BUS312] 3.1-3.4 - Analyze the Data

Bias

prejudice in favor of or against a thing, person, group, or idea

Cluster sampling

random sampling only from specified groupings of the population

Confirmation bias

occurs when analysts analyze/present results in a manner that confirms their existing beliefs or theories while ignoring data and analyses that do not confirm their beliefs

Continuous data

numerical data that can take on any numerical value, not just whole numbers, meaning there is an infinite set of values between any two observations in a ____ ____scale, such as for weight or height

Convenience or non-probability sampling

method of collecting data from convenient, easy-to-access data points

Data distribution

shows all of the possible values for a variable and how often they occur or could occur

Data reduction

the process of reducing the size of a data set to something more manageable and suitable for a business analysis project

Descriptive or summary statistics

summary statistics that briefly describe or summarize features of a data set or variable. The basic ____ _____ include the mean, standard deviation, minimum, and maximum of a data set

Discrete data

numerical data that only take on whole-number (integer) values and have a finite set of values between any two observations. An example of ___ __ is the number of products in inventory (you can have 0 items or 150 items in inventory, but you cannot have 147.8 items in inventory)

Filtering

the process of choosing a smaller portion of a data set for subsequent viewing or analysis

Inference

a conclusion drawn on the basis of evidence and reasoning about the characteristics of a population based on sample characteristics

Inferential Statistics

measures that are calculated using a sample of the desired population. These measures are used to test hypotheses regarding the population

Mean

the average of a set of measurements in a data set

Measures of central tendency

measures that describe the center point of a data set, such as the mean (average), median, or mode

Median

the midpoint of a distribution

Mode

the most common observation in a data set

Nonresponse bias

the partiality (or bias) that results when respondents differ from non-respondents

Outlier bias

the potential disproportionate influence of outliers in study results

Parameter

a characteristic of a population

Population

a group of phenomena that have something in common

Probability distribution

a statistical function that describes the possible values in a population and the likelihood that any given observation (random variable) can take a given range or value

Random variable

a variable used to quantify outcomes of random occurrences

Sample

a subset of members of a population; researchers often select samples that they believe represent the population

Selection bias

the bias introduced by the selection of individuals or data that are likely to sway the results of a study in favor of the analyst's beliefs or hypothesis

Simple random sampling

a sample in which every observation in the population has an equal chance of being selected into the sample

Skewness

the extent to which data are asymmetric about their mean

Statistic

a characteristic of a sample

Stratified random sampling

random sampling from known subgroups to ensure adequate representation in the sample

Symmetrical

used to describe a data set in which the mean, median, and mode are equal. ________ ____distributions have an equal number of values on either side of the middle point of a distribution

Argument

in Excel, a value that a function uses to perform calculations

Interquartile range (IQR)

the midsection of a data distribution, or the range between second and third quartiles

Kurtosis

a measure used to describe a data distribution; it describes the thickness of the tails of a distribution, specifying whether values are more clustered in the peak of a distribution or in the tails. (The tails are the ends of the distribution on either side.)

Measures of dispersion

measures that describe how varied, or dispersed, a data set is

Normal (Gaussian) Distribution

a bell-shaped probability distribution that is symmetric about its mean, with the data points closer to its mean more frequent than the data points further from its mean

Percentile

a value on a scale of 100 that indicates the percent of a distribution that is equal to or below it

Range

a measure of dispersion; the difference between the maximum value and the minimum value in a data set

Standard deviation

the square root of the variance; the dispersion of a data set relative to its mean

Standard normal distribution

a data distribution that has a mean, median, and mode of 0 and a standard deviation of 1

Uniform distribution

a probability distribution in which all outcomes are equally likely

Variance

the average of the squared deviations from the mean for each observation; a measure of dispersion

Z-score

a statistical indicator of how many standard deviations a data point (or observation) is from its population mean