IT-322 Lecture 5 - Chapters 9 and 10
one sample t-test
compare one point of interest to a sample
Control chart basics, three things
data points, centerline (line on mean value) upper control limit and lower control limit
another word for common is....
random
one of the main ideals behind BI and analytics is ..
self serve
Deviation
when values deviate from baseline or historical levels does a change in process have an effect on this?
dependent t-test
when you have 2 samples that end up having to be the same pre/post analysis
Hypothesis testing starts with the assumption that ___________
There actually is no difference between the groups. H0 is null hypothesis.
Hypothesis testing is the use of statistics to determine the probability that a given hypothesis is true.
True
Can Statistical control charts (SPC) can be used to represent the distribution of data????
FALSE, no
One-sample t-test is used to compare the performance of two groups.
False
Statistical tests do not utilize aggregated data
False
Relationship (related to data visualization)
If correlation exists between two or more data points. (waiting in line and leave without being seen rates)
Six sigma uses ANOVA to detect the differences in the performance.
True
Statistical methods are used to identify unusual variations in the performance
True
Statistical procedures can be divided into two major categories: descriptive statistics and inferential statistics.
True
Statistics provides methods to analyze quality and performance of data.
True
Trend over time (related to data visualization)
Used to plot a time series of a variable, for example the number of patient arrivals to the emergency department over the past 30 days
a dashboard is...
a visual display of the most important information needed to achieve one or more objectives, consolidated and arranged on a single screen so that info can be monitored at a glance
causes of variation
common (or random) - these are causes of variation that are inherent in the work being performed special - causes of variation that are external to the system or the work being performed (nurse making a mistake in the system)
ANOVA tests are typically used when you need to...
compare more than 2 samples to each other.
Composition (related to data visualization)
complete picture of a variable summary of the different kinds of lab tests ordered
Comparison (related to data visualization)
contrast different variables # of admissions to each of a hospitals inpatient units over the last month
SPC uses.....
control charts
t-test is used to
determine if a statistical parameter is the same when compared between two groups
The starting point of all data visualizations is to ....
determine the message that is to be conveyed
control charts
evaluate performance and quality with associated rules to determine if a process is in control and improving or getting worse
three causes of poor chart usability
explanation, discrimination, construction
example of special variations
nurse making a mistake in the system
Types of ANOVA tests
one way between groups - when the performance of three or more groups needs to be compared one way repeated measures - when performance has been measured a few times two way between groups - two way repeated measures
what are the two main barriers to self serve
poorly designed portals and stuff taking a long time to run
What are the two main barriers to self serve?
poorly designed portals reports and other tools that take a very long time to run
Agents are
programmed to detect certain predefined conditions or to execute certain business rules scan available real-time data to make sure business rules are being followed?
If a dashboard spans several computer screens then you have made a ....
report
Explanation (chart usability)
some data elements are not explained
SPC stands for....
statistical process control
Hypothesis testing involves a test of _________________
statistical significance
Hypothesis testing
the process of determining whether this difference in values is due to natural variation and chance or the result of the change in process.
what is data visualization?
the process of taking the output from analytical tools and processes and visually representing that info in ways to allow decision makers and QI teams to more easily comprehend and act on that information
small p value means.....
there is a difference, alternate hypothesis is most likely true.
2 sample t-test
to compare the performance of two groups.
Automation enhances the usability of analytics.
true
End users must be involved in the design of dashboards.
true
Poorly designed portal is the main barrier to "self-serve"
true
Statistical methods are used to identify unusual variations in the performance.
true
An example of inferential statistics.
try to see how tall the men of manhattan are. Can't get all the heights, so we infer by getting samples and doing tests. Like t-tests, regression, etc.
Discrimination (chart usability)
when items on the charts are not easily distinguished. Charts designed for color but printed out in black and white
upper and lower control limits are typically drawn at....
3 sigma and -3 sigma above and below.
Example of descriptive statistics
40% of all the dogs sold at this pet shop were terriers
Inferential Statistics
Analyze the sample of data to help make inferences and predictions about a population
Data visualization usage (6 things)
Relationship Comparison Composition Distribution trend over time deviation
alerts / agents are....
Scan for violations of business rules. They can scan real time data
Distribution (related to data visualization)
Study how data points are distributed throughout a data set. wait time distribution for patients on a surgical wait list
Statistical control charts (SPC) can highlight the changes in the process performance. (T/F)
TRUE
in control does not mean an _______ of variation
absence
Tests of statistical significance will help to determine if any observed differences between groups are likely due to __________
actual differences
example of the common variation
actual time differences in admitting patients
alerts are also called
agents
ANOVA Stands for...
analysis of variance
another word for special is....
assignable.
independent t-test
assumes that the 2 populations are indeed independent
control limits
calculated based on the process data itself plotted points of data must always fall between these points
Composition is used to study how data points are distributes through out the data set.
false
The starting point of all data visualizations is to select an appropriate visualization approach.
false
a few design hints (for a dashboard)
focus on indicators most critical to quality <--INDICATORS--> display appropriate indicators don't be afraid to develop multiple dashboards avoid unnecessary clutter and decoration include end users in the design of dashboards make the dashboard as visually appealing as possible
stable
free of special cause variation. Quality means that a process is able to meet target performance on average - but it must accomplish this within certain tolerances and consistency
Essential display components
graphs, icons, text, images
confidence interval
how confident a true value will lie between 2 values
Essential display media components
icons, text, graphs, and images
Data visualization functions 4 things
identifying trends in quality & performance data communication goals and objectives of the HCO sharing results of improvement activities making numerical and statistical analyses more user friendly
Construction (chart usability)
incorrect labels, incorrect tick mars, scales, etc
SPC
is a technique that QI teams use to improve, evaluate, predict, and control process through control charts.
The main purpose of a dashboard is to achieve one or more objectives and therefore ...
it should not be splattered with every indicator and data element available.
Descriptive statistics
large number of values or observations - used to try and provide descriptions of populations (representing entire populations or a sample)
