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
D 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 Math Puzzle Challenge: Fill the white square boxes such that the equations are satisfied Brain Teasers and Puzzles 4
K I’m looking for a square probe for my linear height gauge Manufacturing and Related Processes 1
Cats Clause 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
Ed Panek Looking for Test Resource General Measurement Device and Calibration Topics 0
R Microbiological test (USP61, USP62, USP71, ISO 11137.1, ISO11137.2) --- Testing flow chart Other Medical Device Related Standards 0
S Discussion on OBL and OEM test data for submission as per new EUMDR EU Medical Device Regulations 0
E Do I need test reports for all standards mentioned in my 510k application? Other Medical Device Related Standards 8
C DV/PV Test Part Storage IATF 16949 - Automotive Quality Systems Standard 9
R Statistical Methods for comparing test and reference product equivalence for quality attributes US Food and Drug Administration (FDA) 3
Vader22 5 Why RCA for failure to test Contingency Plan IATF 16949 - Automotive Quality Systems Standard 9
S Knee-Patella wear test CE Marking (Conformité Européene) / CB Scheme 4
L PFMEA for test procedures (ISO 14971) ISO 14971 - Medical Device Risk Management 5
A Direct vs. Post-License Investigational Test Authorization (ITA) Canada Medical Device Regulations 0
P Test Method Validation (TMV) for all Measurement Methods in Rec/Inspection Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
L AS9100 Section 8.4.2 - External provider test reports AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 10
E How to test 8.7.4.7 d) ? What "not protectively earthed accessible part" means? IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
T ANOVA analysis to find F test. Using Minitab Software 3
P API Q1 - Monogram Product & API 4F - Proof Load Test Oil and Gas Industry Standards and Regulations 3
D Test Management Software Software Quality Assurance 1
B How to test operator to see if they can catch the defective parts? Manufacturing and Related Processes 8
G 60601-1 8.8.3. short circuit of both side during insulation test IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
K Bacterial Endotoxin test for Purified water Manufacturing and Related Processes 2

Similar threads

Top Bottom