Elementary Statistics Flashcards
Descriptive Statistics
Summarizing information in a convient form
Inferential Statistics
Using the same data to make estimates, decisions, predictions, etc. from a large amount of information
Unit
What or who we are studying
Sample
A subset of the population
Representative Sample
Sample with characteristics similar to the population
Simple Random Sample
Every member of the population had an equivalent chance to make it to the sameple
Sampling Error
Discrepancies in the random sample that don’t represent the population
Sampling Bias
Error caused by nonrandom sample
Variable
characteristic of the unit we are interested in studying
Selection Bias
Individuals choosing whether or not to be part of the sample or people only answering if they loved/hate something - no between
Non-Response Bias
Individuals who are unwilling or unable to take part in the research study (ex. forgotten surveys)
Measurement Error
Inaccuracies in the values being recorded
Quantitative
Data that are numeric
Qualitative
Data that are categories
Discrete
Countable/Definable number of options
Continuous
Infinite number of options
Published Source
Find our data that someone else found and published it
Experiment
Experimenter has control collecting data
Survey Techniques
Questionnaires, problems: someone has to write the surveys which could create bias
Observationally
Experimenter with a clipboard collecting data
Mean
Average of the data
Median
Middle number of the dataset
Mode
Most frequent occurrence in the data set
Skewed Right
Median > Mean
Skewed Left
Median < Mean
Symmetric
Median = Mean
Deviation
Distance from a point to the mean
Percentile Rank
The observation set where the number p percent of the observation are below
Z-score
How many standard deviations an observation is from the mean
Outlier
Lies outside of our general data set
|z| >= 3 is considered an _____
