Chi-square test - What do I do next?

B

big_tj

#1
Hey guys

I did a Chi-square test and found out that that there was a statiscally significant difference among figures from my 3 units. I was testing to see if there was a statistical difference between the % (yes/no) of some results of 3 units.

Now that there is a difference that is statiscally signifant, what tool do I use to find out which is statistically differnent from the others? I was thinking that i might have to do different chi-square tests on the result of each unit two at a time and see which "set" produces a statistically significant variance; would that work? If this approach does work, is there a simplier way - I ultimately need to do some comparison between results of approximately 10 units.

Also, how can i statistically show which result is the top result?

:frust:

Thanks!
 
Last edited by a moderator:
Elsmar Forum Sponsor

Steve Prevette

Deming Disciple
Staff member
Super Moderator
#2
What I do is look at the chi square inputs from each of the individuals. Any that exceed 9 (three standard deviations) are likely significantly different from the others, any that exceed 4 (two standard deviations) are suspect.

input = (Measured - Expected)squared divided by Expected
 
B

big_tj

#3
What I do is look at the chi square inputs from each of the individuals. Any that exceed 9 (three standard deviations) are likely significantly different from the others, any that exceed 4 (two standard deviations) are suspect.

input = (Measured - Expected)squared divided by Expected
Hmmm...interesting perspective; never thought of that. Thanks a lot; I will see if that works!

Can you expound a bit more on the 9 equating to three standard deviation?
 
Last edited by a moderator:
Thread starter Similar threads Forum Replies Date
V Modified chi square statistic test (mCSRS) Statistical Analysis Tools, Techniques and SPC 1
M Help me understand how to conduct a Chi Square Test Statistical Analysis Tools, Techniques and SPC 3
O Chi Square Normality Test using Microsoft Excel Excel .xls Spreadsheet Templates and Tools 2
K Multiple Comparison in Chi Square - More than 2 Rows/Columns in Contingency Table Using Minitab Software 9
B Using Minitab for Chi Square using Weighted Cases Using Minitab Software 2
S Chi-Square Conundrum - Analyzing tree death across 3 areas Inspection, Prints (Drawings), Testing, Sampling and Related Topics 13
M Chi Square Help - One of my variables has three possible results Using Minitab Software 15
Darius t2 Hotelling or Chi square Control Charts - How is done - Calculus and charting? Statistical Analysis Tools, Techniques and SPC 2
S Layman's Learning Tool Needed - Regression analysis, t-tests, chi-square tests, etc. Statistical Analysis Tools, Techniques and SPC 5
S Assessments of Normal Distribution - Formulae for CHI squared, Kurtosis and Skew Statistical Analysis Tools, Techniques and SPC 1
K I’m looking for a square probe for my linear height gauge Manufacturing and Related Processes 1
C Standard for Calibration of Engineers Square General Measurement Device and Calibration Topics 2
P Purpose of calculating Ta, Tb & R Square in Linearity Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
P ASTM Standard, Stainless Steel angle that has been rejected because it is not ?square Manufacturing and Related Processes 2
V Lack of Fit vs Pred-R-Square. Using Minitab Software 3
L Gauge to test and verify a Set Square Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
F Developing a Robust MSA Program - over 35,000 gages in 1 million square ft. facility Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
A Test Probes for measuring ohms per square on shielded plastic surfaces Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
I Partial Least Square Regression Result - Question Using Minitab Software 3
E Interpreting Partial Least Square Results Using Minitab Software 1
J TSC on blueprint "to square corner" - Meaning? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 7
M Universal Master Square/Toolmakers Surface Plate Square Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
N How to Calculate a True Position on a Square Slot - GD&T Inspection, Prints (Drawings), Testing, Sampling and Related Topics 9
Jim Wynne Checker Square Optical Illusion Coffee Break and Water Cooler Discussions 14
J Work Instruction to Calibrate or Verify a Combination Square General Measurement Device and Calibration Topics 15
ScottK Root Sum Square and Statistical Tolerancing help needed Statistical Analysis Tools, Techniques and SPC 5
E S-Square Control Chart - Is anyone familiar with the S-Square Control Chart method? Statistical Analysis Tools, Techniques and SPC 2
B Square Root of n+1 Question Statistical Analysis Tools, Techniques and SPC 3
Z Welding Expert Needed to help us - Square Aluminum bar to be welded Manufacturing and Related Processes 4
Scott Catron Statistical basis for square-root sampling Inspection, Prints (Drawings), Testing, Sampling and Related Topics 11
E When to perform accelerated aging studies and transport test(OQ or PQ) Qualification and Validation (including 21 CFR Part 11) 1
U Does *anyone* know a lab that will test to EN 455-4 Medical Gloves shelf life determination? EU Medical Device Regulations 1
A Test requirements for marketing in US when RATED values are not of US IEC 60601 - Medical Electrical Equipment Safety Standards Series 5
H Secondary Circuits, Voltage Test and Clearance/Creepage IEC 60601 - Medical Electrical Equipment Safety Standards Series 0
S Fogging test as per DIN 75201(50ug/g ) VDA Standards - Germany's Automotive Standards 3
R HV Test of HF Surgical Unit IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
R IEC 60601-1 - 11.1.3 e) Test criteria - Temperature Measurements IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
E 60950-1 resistance to abnormal heat test Various Other Specifications, Standards, and related Requirements 0
S User evaluation for self monitoring blood glucose test systems US Food and Drug Administration (FDA) 4
E MSA for Push and Pull test Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
Z IEC 60601-2-25; Frequency response test Medical Device and FDA Regulations and Standards News 1
J Confusing on Harmonic Emissions/Voltage Fluctuations/Flicker test for CISPR 11 Class A Equipment IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
E Routine production tests - dielectric voltage withstand test IEC 60601 - Medical Electrical Equipment Safety Standards Series 4
D Test Method Validation Qualification and Validation (including 21 CFR Part 11) 4
Crimpshrine13 Laboratory Scope - Calibration vs. Test Methods - IATF 16949 IATF 16949 - Automotive Quality Systems Standard 3
N IEC 60601-1-1 - Stress test, reference voltage IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
R Accelerated Aging - Creating test samples - Implantable medical device Question Other Medical Device Related Standards 4
E Mentor for Test Method Validation (TMV) Design and Development of Products and Processes 2
L ASQ's Biomedical Auditor Course Test ASQ - American Society for Quality 1
W Regarding Requirement for Hi pot & Leakage Current test Station Set-up IEC 60601 - Medical Electrical Equipment Safety Standards Series 6

Similar threads

Top Bottom