Module 3/ Quiz 2
At the highest point on the y axis of a survival curve everything is
alive
Used to show the relationship between a continuous and categorical variable, data is summarized by using "box and whiskers"
box plot
What is Kelvin?
A ratio, it has an absolute zero (0= absence of heat)
Outcome Variable
Dependent Variable
The middle score of the data set for a set that has been arranged in order of magnitude
Median
The gold standard for skewed data
Median or Interquartile Range
Long tail to the left, mean is on the left side of the peak
Negative Skew
Can nominal data be ranked?
No
Gender
Nominal
Looking at genetics overtime and tracking that down
Phylogenetic Tree Plot
2 Examples of Tree Plots
Phylogenetic and Decision
Nominal/ Ordinal Measurements = _____ Graph
Pie Chart/ Bar Graph
Measure of CT used for nominal data
mode
Numeric values that can be ordered sequentially and that do not naturally fall into discrete ranges
continuous
A branching chart that represents the logical sequence or pathway of a clinical or public health decision
decision tree
A box plot will display extreme
outliers
Used to describe, show, or summarize data in a meaningful way
descriptive statistics
A graph in which you are charting categorical data vs. continuous, the dots will make bars
dot plot
Example of percentile
growth charts
Continuous level of measurement where there is a meaningful zero
ratio
Chart in which there are spaces in between categories, the information is in nominal order
Bar Chart
What kind of graphs exhibit nominal data?
Bar graph, pie chart
How can we assess outliers in the data?
Box Plot, Bell Curve, Histogram, Measures of Central Tendency(Mean/Median/Mode)
In a basic data file, what is entered into the rows of the data set?
Cases; Information on individual case or person
Measure that provides a single value that summarizes an entire distribution of data
Central Location/ Central Tendency
Comparison of studies for a meta-analysis, compares same stat across ALL studies
Forest Plots
Descriptive statistics that uses ordinal data?
Frequencies, mode, median, percentiles
Chart used with continuous data, no categories or ranges
Histogram
Interval/Ratio Measurements = __________ Graph
Histogram
Graphs that use ratio
Histogram, boxplot, stem & leaf
Measure of CT to use at least ordinal and interval level; can have a skew in fact it is a way to deal with skew
Median
Manipulated Variable
Independent Variable
Midpoint of the data
Median
Allows conclusions to be drawn, used to make inferences
Inferential Statistics
The data that falls between the third quartile and the first quartile
Interquartile Range
The middle 50% of the data; used most commonly with the median
Interquartile Range
Hemoglobin A1C
Interval
Continuous data where there is equal distance between the values and no absolute zero
Interval Data
temperature in Fahrenheit, standardized exam score
Interval Measurement
Higher level data use?
Interval or Ratio
What measure of CT is particularly susceptible to outliers?
Mean
A model of your data set; the most common value
Mean (Average)
In a normal population what is the same
Mean, Median and Mode
3 Measures of Central Location
Mean, Median, Mode
Descriptive statistics that uses ratio data?
Mean, SD, Skewness, Kurtosis
The most popular option or most frequent score used by the data set
Mode
Nominal Means
Name (race, religion, marital status, color)
Categorical data that ranks data but difference between the ranks is unknown
Ordinal Data
Ranking of favorites, Student letter grades, Race finisher, Likert scale
Ordinal data
When mean, median and mode are not the same number
Outlier
Numbers that can throw off/skew the data
Outliers
Skews are caused by
Outliers
Range from 0-100, splits the results into 100 pieces and sees how many fall above and below that value
Percentile
Long tail is on the right, mean is on the right side of the peak
Positive Skew
Variable View
Yellow tab at bottom left, columns are looking at different aspects of the variables
Formula for figuring out Interquartile Range
Q3-Q1, Represents the central portion of distribution from 25th to 75th percentile
Data View
Yellow tab at bottom left, row- cases and columns- variables; looks the same as other basic data files
Maximum-Minimum in a spread
Range
Maximum-Minimum, Reported as a single number
Range
5 Measures of Dispersion?
Range, Standard deviation, Quartiles/Interquartile Range, Variance, Percentiles/ Percentages
Height, age, weekly food spending
Ratio
The most detailed level of measurement
Ratio
Diagram between two continuous variables
Scatter plot
A representation of not having enough data to represent the population
Skew
How data is spread around the central point?
Spread (dispersion)
Uses a formula that uses the mean, HAS to have a normal distribution
Standard Deviation
What is the gold standard for scale data that is normally distributed?
Standard Deviation and Mean
Refers to the variability we might expect in the arithmetic means of repeated samples taken from the same population
Standard Error
An absolute number, percentage or proportion of survival over time; Shows differences in groups or one group
Survival Curve
We choose which mean/median/mode to use based on what two things?
The level of measurement; the skew
On a survival curve time is always_____, and survival is always ______
Time=X; Survival=y
A characteristic that can vary (i.e. height, sex, vaccination status)
Variable
In a basic data file, what is entered into the columns of the data set?
Variables; info for each variable; ex: race, date, birth
Needs Normal distribution, uses the mean
Variance
Vertical
Y-Axis
A dot plot uses dots to show the relationship between a categorical variable on the ______-axis and a continuous variable on the _______- axis
X- categorical, Y- continuous
Horizontal
X-Axis
Is Median susceptible to outliers or skewed data?
Yes, but less affected than mean
Can you have more than one mode?
Yes; Bimodal
what type of graphs use ordinal data?
bar graph, pie chart, stem & leaf
Cannot be sequentially ordered or differentiated from each other using a mathematical method
categorical
Descriptive statistics are measures of
central tendency and dispersion
A forest plot is also called a
confidence interval plot
A square, with branches, representing the choices in the decision-tree diagram
decision node
Descriptive statistics that use nominal data
frequencies, percentages, can determine mode
The ____________ variable influences change in the ___________ variable
independent; dependent
Measure of CT in which you at least need scale level data, has to have a normal distribution
mean
Descriptive statistics that uses interval data?
mean, median, SD, skewness and Kurtosis
Examples: yes/no, marital status, type of car owned
nominal data
categorical data that is discrete/ arbitrary
nominal data
Satisfaction with healthcare measured on a 4 point scale with 1= not satisfied and 4= extremely satisfied
ordinal
What can you find under measure in the variable view?
ordinal, nominal, or scale options
The number over 100 , how much of a population takes up that space
percentage
The line in the middle of a box plot represents
range
A graph in which everything runs together, continuous vs continuous
scatter plot
If everything is perfectly lined up there is said to be no
skew
Normal distribution has no
skew
What type of graphs use interval data?
stem & leaf, boxplot, histogram
The first column or variable of an epidemiologic database usually contains
that person's name, initials, or identification number
Does ordinal data have rank?
yes, but intervals between ranks are not equal