Basic Vocabulary
What is the difference between a statistic and a parameter?
A statistic is a numerical summary of a sample, while a parameter is a numerical summary of a population.
Which of the following is NOT an appropriate way to obtain a SIMPLE RANDOM SAMPLE?
A. Selecting the first 5 names off a list.
B. Using a random number generator to find participants.
C. Placing names in a hat and shuffling the names.
How do you find the "relative frequency" for a RELATIVE FREQUENCY DISTRIBUTION?
FREQUENCY/SUM OF ALL FREQUENCIES.
What are the different types of observational studies?
1. Cross-Sectional
2. Case-Control
3. Cohart
What is a "margin or error"?
-The amount of percentage points your results will differ from the actual answer.
What are the 4 levels of measurement?
Nominal, Ordinal, Interval, and Ratio.
Name the 4 other types of sampling methods.
1. Stratified.
2. Systematic.
3.Cluster.
4. Convenience.
What type of graph is a "PARETO CHART"?
-A bar graph whose bars are drawn in decreasing order of frequency or relative frequencies.
What is a "lurking variable"?
A variable that was NOT considered initially when conducting a test, but affects the response variable.
What is the key difference between DESCRIPTIVE and INFERENTIAL stats?
Descriptive Stats consists of organizing and summarizing data, while Inferential Stats uses methods to take a result from a sample, extend to a population, and measure the reliability of that result.
What is the difference between QUALITATIVE AND QUANTITATIVE data?
Qualitative - uses characteristics to describe data.
Quantitative - uses numerical values to describe data.
How does BIAS occur in sampling?
When the results from the sample are not representative of the population.
What are the different shapes of a distribution?
1. Uniform
2. Bell-shaped.
3. Skewed-Left.
4. Skewed-Right.
This type of observational study is considered to be "RETROSPECTIVE".
Case-Control.
What is the number that makes a probability "low" or "unlikely" to occur?
5% or below.
What is the difference between DISCRETE AND CONTINUOUS data?
Discrete data is COUNTABLE number, while Continuous data is not.
*DISCRETE = WHOLE NUMBERS*
*CONTINUOUS MAY INCLUDE FRACTIONS AND DECIMALS.*
What are the 3 types of bias?
1. Sampling Bias.
2. Nonresponse Bias.
3. Response Bias.
When constructing a HISTOGRAM, what is the formula for finding the CLASS WIDTH?
LARGEST DATA VALUE - SMALLEST DATA VALUE
________________________________________
NUMBER OF CLASSES
*round UP to a convenient #.
What is the difference between an observational study and a designed experiment?
Observational studies measure the value of the response variable without attempting to influence the outcome.
Experiments are conducted by selecting random individuals and intentionally manipulating the value of the explanatory variable, while controlling the other explanatory variables at fixed values.
How would you obtain a sample from a random number generator using STATCRUNCH?
1. Select DATA menu.
2. Select SIMULATE.
3.Select Discrete Uniform (equally likely chance of occurring).
4. Specify ROWS & COLUMS.
5. Enter MAX & MIN.
6. Specify seed. (given = fixed).
7. Compute!
What is a "level of confidence"?
A measure of reliability.
How does a NON-SAMPLING ERROR occur?
Results from under coverage, nonresponse bias, response bias, or data-entry error.
What is one key difference between a BAR GRAPH and a HISTOGRAM?
In a histogram the bars (rec) are touching each other vs. the bar graph whose bars may not touch due to data.
What is web scraping/ data mining?
The process of extracting data from the internet.
In INTERVAL NOTATION, explain the difference in meaning between the BRACKET ([) and PARENTHESES (().
Bracket = the # is included.
Parentheses = the # is NOT included.